Howdy partners, welcome to my guide for RDR2! Be careful while using it, because there are a lot of spoilers here so make sure you will not destroy your experience first (I will add some extra spoiler alerts of course). Be extra careful with achievements Paying Respects and It's Art - HUGE Spoilers!
I was able to create this because I already finished the game on Xbox One so I can explain most of the trophies.
There are total of 51 achievements - 10 story line, 17 online and 24 side trophies (5 of them are very hard and time-consuming)
If you have any questions, if you find any mistakes or if you know something I don't and should, feel free to write it in the comments section.
Enjoy!

Just a Scratch
Complete 'Enter, Pursued by a Memory'


Back in the Mud
Complete Chapter I


To Greener Pastures
Complete Chapter II


Settling Feuds
Complete Chapter III


Washed Ashore
Complete Chapter IV


No Traitors
Complete Chapter V


Third Time Lucky
Complete 'Goodbye, Dear Friend'


Redemption
Complete 'Red Dead Redemption'


Cowboy Builder
Complete 'A New Jerusalem'


Endless Summer
Complete the Epilogue

Discover the fate of Marko Dragic
There are three side missions about M.Dragic. You can meet him for the first time in Chapter IV next to the small lake in Saint Denis between 6am and 6pm. After you complete the last mission for him, wait 48 in-game hours and come back to his lab. You will find a lamp next to his body. If you pick it up, the achievement will pop up.

Attain 100% completion
You can follow your progress on Rockstar Games Social Club [socialclub.rockstargames.com]!

For 100% completion you will have to:
-Finish the main story line (107 missions),
-Finish at least 10 stranger missions (question marks on your map),
-Finish 5 bounty hunter missions (you can start them by visiting sheriff's office in Valentine),
-Come across 25 chance encounters (e.g. a man bitten by a snake, random shootouts, some fella lost in the forest, woman whose horse died etc.), they are completely random so you have to travel a lot,
-Encounter one gang ambush (you will experience it even more than once),
-Capture 6 gang hideouts (you should do it during the main story line),
-Have a Bath,
-Go to the Theatre,
-Play a game of Blackjack,
-Play a game of Dominoes,
-Play a game of Five Finger Fillet,
-Play a game of Poker,
-Make a sketch of at least one point of interest,
-Find 9 graves of your fallen gang members (see Paying Respects trophy),
-Find at least one buried treasure (there are many maps leading to the treasure, you can purchase the first map from Maximo; you can meet him in Chapter II near Flatneck Station. He will offer to sell you the map for $10 if you accept and $5 if you decline. You may also rob him),
-Complete at least one set of cigarette cards,
-Complete 'A Fisher of Fish' stranger mission:
You can start this mission by speaking to Jeremy Gill on his dock along the north-east shoreline of
Flat Iron Lake (south-east of Flatneck Station). You will receive a map with locations of 13 Legendary Fish. When you catch them all, go to the Post Office and mail them to Jeremy.
-Complete 'A Test of Faith' stranger mission:
East of Flatneck Station, on the field you can find a woman next to a wagon, trying to pull something out of the ground. Talk to her and she will ask you to help her find 30 dinosaur bones.
Here's a helpful video guide. You can use Eagle Eye to find them easier.
-Complete 'Duchesses and other Animals' stranger mission:
In Chapter IV, in North Saint Denis you can meet Algernon Wasp, who is a collector of exotic things. He will give you a list with things he needs. When you return to him with all the items he wanted, you will receive another list (there are 5 lists total).
-Complete 'A Better World, A New Friend' (see It's Art trophy),
-Complete 'Geology for Beginners' stranger mission:
For this mission you will have to find Francis Sinclair, who is in his cabin to the northwest of Strawberry (does his scar seems familiar to you...?). He will tell you to find 10 rock carvings. Here's a helpful map in the worst possible quality i was able to find :v
-Find 20 dreamcatchers:
You don't have to start any mission to do it. If you see a dreamcatcher hanging on a tree, approach it and investigate it. This map might help. At first, the locations of the dreamcatchers will seem quite random. Even after knowing where to look, spotting them can be difficult. The first trick is to look for trees that seems different among their surroundings. Some might look like a different type of tree, some might be dead and others might be alone.
-Hunt down 5 Legendary Animals,
-Study 50 different types of animals,
-Obtain 10 different equipment items,
-Fish 10 different types of fish,
-Discover 6 gangs,
-Discover 20 different types of plants,
-Discover 10 different breeds of horses,
-Obtain 48 different weapons,
-Craft one recipe from each category,
-Get maximum level of Health, Stamina and Dead Eye,
-Achieve maximum bonding level with your horse (see Trusty Seed trophy)
-Complete every challenge (Bandit, Explorer, Gambler, Herbalist, Horseman, Master Hunter, Sharpshooter, Survivalist, Weapons Expert),
-Find 5 different shacks,
-Interact with 5 special characters (e.g. War Veteran or Blind Man),
-Perform every type of robbery (house, train, shop/bank and coach).

Survive 3 days holding a bounty of $250 in all states
This trophy looks hard, but actually it's quite simple. The best way to get it is to shoot people in villages or towns, so that somebody can see it and let the local sheriff know. When you finally get $250 bounty in all states (You don't have to do it in New Austin before the Epilogue!) just go to your camp and sleep, then maybe try to go somewhere by train so the time will pass faster. If you are wondering how to get that high bounty in Ambarino, the best (and the only) way is to stop the train there and just kill all the folks, then wait for the law and simply kill them too. Repeat until your bounty is $250.
Remember to save your game before doing this achievement!

Recover the stash from 4 homesteads
There are 7 stash locations in the game, but you only need 4. Here is a map with all of them.
I personally did it by a total accident doing side missions and just exploring the world, so there is a big chance you will do the same.

Complete one of the Collectable strands
There are four collectable strands:
-30 dinosaur bones,
-10 rock carvings,
-144 cigarette cards,
-20 dreamcatchers.
You can collect all cigarette cards very fast if you did all the story line missions!
First you have to start a stranger mission ''Smoking and other hobbies'' in Chapter II. Then, after beating the epilogue, go to the general store and keep buying premium cigarettes until you get all the cards (you can check it in menu>progress>compendium). After that just go to the nearby post office and send all the cards to your ''client''. This method takes about 20 minutes and +- 1000$.
If you want to collect something else than cards, see Best in the West achievement.

Deliver 5 camp companion item requests
This trophy can be missed if you don't do it before Chapter V!
Sometimes when you are in the camp, gang members may ask you to bring them an item they need. Usually they ask you for it if you talk to them, but sometimes they will approach you directly. There are total of 20(?) item requests, but you only need 5 for the trophy. Here are 5 easy examples (you can do them all in Chapter II so it's more comfortable)
1.5$ for Abigail
Talk to her while she is with Jack in their tent between 8am and 8pm and just give her the money.
2.Comic book for Jack Marston
You will get this request automatically during the story mission ''A Fisher of Men''.
You can find this item in a little house nearby Emerald Ranch
3.Rabbit for Mr. Pearson
Start with talking to Pearson when he's drinking a beer behind his wagon (8am-2pm). Rabbits can be found almost everywhere, just hunt one and bring it to your camp chef (You can't give it to him directly, you have to donate it to him by using his table)
4.Kentucky Bourbon for Sean
Interact with him while he's making fire bottles in a camp (8am-6pm). Kentucky Bourbon is a popular item, you will probably have one in your inventory. If not, go to the store and buy it for 3$.
5.Hair Pomade for Bill
Interact with Bill Williamson while he's sitting on the chair next to his tent between 8am and 8pm. You should have some hair pomade with you, if you don't you can always buy it in most of the stores.

Reach maximum or minimum Honor level
Your Honor status may be changed in many ways - helping random strangers, killing or robbing them, doing missions or even greeting random people, everything matters. You just have to choose your path and either be an evil outlaw or a good boah. It's up to you!
I personally recommend reaching maximum Honor level. It unlocks some cool stuff and decrease prices, but it's also very important in the last chapter!

Complete a Companion Activity in each camp
For this achievement you need to complete one companion activity in camp in Chapters II, III and IV.

Here is the list of all available activities:
Chapter II
-Hunting with Charles,
-Five Finger Fillet with Lenny,
-Home Robbery with Javier
Chapter III
-Five Finger Fillet with Micah,
-Fishing with Javier or Kieran,
-Home Robbery with Sean
Chapter IV
-Coach Robbery with Micah or Lenny,
-Hunting with Pearson

Donate $250 to the gang tithing box
I believe I don't have to explain this one.

Earn 70 Gold Medals in Story missions
Flashbacks from GTA V? Yeah, me too.
This trophy is very hard and time-consuming. To earn a gold medal on a mission you have to do all the tasks attached to it, for example let's see the first mission of Chapter I - 'Outlaws from the West'. The special tasks are:
-Take no damage during the shootout
-Loot 6 or more items from Adler Ranch
-Complete with at least 80% accuracy
You have to do all the tasks in one run!

You can find all the missions in Menu>Progress>Story

Survive 18 bear attacks and kill the bear each time in Story Mode
When you find a bear you have to let him attack you and knock you on the ground. While he is scratching and biting you, spam F to break free. After you stab him with your knife, there is an opportunity to shoot him (shotgun is the most effective option).
You have to kill the bear when you are still on the ground, otherwise it's not going to count!

Play all mini games
There are 4 mini games total:
Poker - main Saloon in Valentine; there is also a story mission connected with poker
Dominoes - Emerald Station or your camp
Five Finger Fillet - You can play this very safe game in Valentine or in your camp with Micah or Lenny
Blackjack - Big Saloon in Rhodes
You don't have to win any of them to get the trophy, it's enough if you just play one round.

Find a permanent home for the squirrel statue
SPOILER ALERT
This trophy can be achieved only after beating the epilogue.
To start you will have to visit the Valentine train station and find a poster on the wall, the hunt begin after you read it. There are 5 hunting requests:

Hunting Request 1:
Perfect Squirrel Carcass
Perfect Rabbit Carcass

Hunting Request 2:
Perfect Cardinal Carcass
Perfect Rat Carcass
Perfect Woodpecker Carcass

Hunting Request 3:
Perfect Chipmunk Carcass
Perfect Oriole Carcass
Perfect Robin Carcass
Perfect Opossum Carcass

Hunting Request 4:
Perfect Sparrow Carcass
Perfect Songbird Carcass
Perfect Toad Carcass
Perfect Bullfrog Carcass
Perfect Skunk Carcass

Hunting Request 5:
Perfect Waxwing Carcass
Perfect Bat Carcass
Perfect Blue Jay Carcass
Perfect Crow Carcass
Perfect Beaver Carcass

Useful tips:
Use bow with small game arrows if you hunt tiny animals like blue jays or rats and varmint rifle for bigger ones (rabbits, skunks, beavers and opossums).
To increase quality of hunted animals, you should use Buck Antler Trinket (kill Legendary Buck, then buy the trinket at the Fence).
You should send the carcass to L. Hobbs on the post office asap.
Don't skin or pluck hunted animals!

After you have completed all the hunting requests, wait 24 in-game hours for the invitation from L. Hobbs, then visit her in her house near Strawberry. You will receive a Squirrel Statue dressed like John. Take it to your home and place it on top of the fireplace in the living room, then leave the house and come back after 24 in-game hours. Now you will have to find the statue, place it on the fireplace and wait 24h six times. The locations are:
1. Chest in John’s Bedroom
2. Chimney in John’s Bedroom
3. Uncle's Room inside a chest (you can get there by using a ladder in the kitchen)
4. Next to the barn, inside the wheelbarrow in the sheep area
5. In the chest inside a barn (up a ladder)
6. Top of the Mount Shann in West Elizabeth - You will unlock the achievement after you pick it up

Catch a fish weighing at least 16 lbs (7.3 kg)
If you like fishing you will probably unlock it by accident, if not - just try to catch a big fish using special lures

Complete all optional Honor story missions
It's good to save your game every few hours while doing this trophy.
The Honor story missions are special, because we can choose between helping someone or not (always choose to help if you want to get this achievement!).
Here's the list with all of them:
Chapter II:
'We Loved Once and True' I, II & III
'Good, Honest, Snake Oil'
'Money Lending and Other Sins' I, II & III
Chapter III:
'Money Lending and Other Sins' IV
'The Curse of True Love' I, II & III
Chapter IV:
'Money Lending and Other Sins' V
'Help a Brother Out'
'Brothers and Sisters, One and All'
'Fatherhood and Other Dreams' I & II
Chapter VI:
'Money Lending and Other Sins' VI & VII
'Of Men and Angels' I & II
'Do Not Seek Absolution' I & II
'The Course of True Love' IV & V
'Honor, Amongst Thieves'
'Archeology for Beginners'
'Mrs. Sadie Adler, Widow' I & II

Upgrade each available component for a single sidearm or longarm weapon
Go to the gunsmith and simply upgrade the weapon of your choice. You have to customize all the components. If you didn't unlocked the achievement after that, try to upgrade components for another weapon.

Find the graves of each of your fallen companions
SPOILER ALERT
After beating the epilogue you have to visit 9 graves of your dead friends. Here's a map with all of them. I will give you more accurate location so it's easier to find it.
1. Jenny Kirk














2. Davey Callander














3. Sean MacGuire


















4. Kieran Duffy














5 & 6. Hosea Matthews and Lenny Summers (you have to interact with them separately)

















7. Eagle Flies














8. Susan Grimshaw















9. Arthur Morgan

Spend $5000 across all shops
When you manage to collect this amount of money, simply save the game and keep buying stuff e.g. horses and clothes.
You will get a lot of cash in the epilogue so don't worry.

Craft 30 unique items in Story Mode
Crafting is available in your campfire, just set a small camp somewhere safe. You will have to craft 30 different items for it, but don't worry, you have a big choice. Everything counts, from food and horse stimulants to ammunition and weapons. If you don't have enough resources to craft something, you can always go to the store and buy them.

Skin every species of animal in Story Mode



Study every animal across all states in Story Mode



These two achievements are very similar and you can do both at once by making sure that you will study the animal before killing it (keep the safe distance while dealing with predators and use your binocular). I strongly recommend doing this trophy after beating the epilogue, because it is the only moment you can achieve it (one more animal is added in the end).
You will need to find 169 out of 178 animals in the game (there is no need to kill animals like chickens or dogs, it is enough if you study them).
SPOILER ALERT!
You don't need animals from the Guarma Island for this achievements.

Rob or loot $250
The easiest way to do it is just looting dead enemies, they usually have ~$2 with them, sometimes more. Just kill some ♥♥♥♥♥♥♥♥ O'Driscolls and loot them, it is not only a pleasure but also a duty.

Reach max bonding level with a horse
Take good care of your horse. Pet him, feed him, brush him when he is dirty and calm him when he is afraid. If you are nice to your horse, I'm sure you will reach max bonding level soon.

Complete 10 Stranger mission strands
During your gameplay, sometimes you will spot black question marks on your map. If you go there and speak to the stranger you just met, you will begin a side quest called stranger mission. There are 24 stranger missions total, but you need only 10 for this achievement. Here's a full list of them and when you can find them
Chapter II:
'A Test of Faith'
'The Noblest of Men, and a Woman'
'All That Glitters'
'Arcadia for Amateurs'
'Smoking and Other Hobbies'
'American Dreams'
'A Fine Night for It'
'Geology for Beginners'
'Fundraiser'
'The Smell of Grease and Paint'
Chapter III:
'He's British, Of Course'
'The Iniquities of History'
'A Fisher of Fish'
'No Good Deed'
Chapter IV:
'Oh, Brother'
'The Artist's Way'
'Duchesses and Other Animals'
'A Bright Bouncing Boy'
'The Mercies of Knowledge'
'Idealism and Pragmatism for Beginners'
Chapter V:
'The Wisdom of the Elders'
'The Widow of Willard's Rest'
Chapter VI:
'The Veteran'
Epilogue:
'The American Inferno, Burn Out'

Breakout
Complete the Intro


Series Major
Take part in a Series


Getting Started
Reach Rank 10


Notorious
Reach Rank 50


Posse Up
Form a Persistent Posse


Home Comforts
Purchase 5 camp improvements


Buckle Up
Achieve 5 gold belt buckles from awards


Strength in Numbers
Complete a Free Roam mission as part of a Posse with at least 2 members


Picked to Perfection
Pick 25 Herbs


Gun for Hire
Accept 10 Free Roam missions from characters around the world


Butchered
Sell 20 items to the Butcher


Eventful
Play 5 Free Roam Events


Master Craftsman
Craft 20 items (excluding ammo)


Non-Regulation
Craft 25 pieces of ammunition


Horses for courses
Concurrently own 5 horses


All's Fair
Successfully counter a rival Posse's Free Roam mission


The Real Deal
Achieve MVP 3 times (in a round with at least 4 players)