Since there are no missable achievements, there's only one info you should know as early as possible for this game:

All the achievements are tied directly to the ingame "Hunter Profile" awards. As such, ALL the achievements for this game NEED to be earned on the SAME ingame character in order to unlock the required award associated to:


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If you've got any questions about the game outside of achievements, Minorou got you covered:

• https://gtm.steamproxy.vip/sharedfiles/filedetails/?id=3435494189

And if you just want to re-read any ingame tutorials, navigate to:

• 

Complete the main story.



Don't get confused or shocked about the Hunter Rank 100 requirement, if you're still in the early parts of the story. Your Hunter Rank is hard-locked during the first 3 chapters, but will increase MUCH faster from chapter 4 onwards.
Once it unlocks, you'll start to earn a certain amount of Hunter Rank points for each monster hunted and each quest completed. Some late game quests can even give you an entire rank up on their own.
Your Hunter Rank will get frozen again on rank 15, 20 and 40, until you clear the story quests unlocked at these thresholds. ALL earned Hunter Rank points will be saved in the background though. So you can do the story at your own pace. For example, my Hunter Rank jumped from 40 straight to 56, immediately after clearing the corresponding story quest.

That being said, this achievement progresses passively, can be sped up depending on your choice of quests, and is basically impossible not to obtain along the way to all other achievements.

While out in the field, open your map, hover over a large monster or select it from the Environment Overview and click "Details" -> "Create Quest".
You can choose between hunting it right away -> Field Survey, or later -> Investigation.
Ironically, Field Surveys are also available right away from the beginning of the game, while Investigations only become available later during chapter 4 of the story.



Simply walk towards a monster without being noticed and press the button prompt displayed roughly in the middle of the screen. Works both at the start of a quest and every time the monster changes locations.
Equipping the Ghillie Mantle from your item bar (unless disabled at camp) makes this all but guaranteed.



Hit a monster a few times with *jump attacks* and you'll mount it. From there, spam the knife attack until you can perform the weapon finisher. Do that one and the achievement unlocks.

*Jump attacks refer to attacks performed after your character performed a natural jump from an elevated position of the surroundings, or the jump attack from the back of your Seikret. For weapon-exclusive moves, only some of the Insect Glaive's attacks count towards this.



Once you've hit a body part repeatedly, the damage numbers will take on a darker hue of orange with little markers around the corners. From there, press the Focus Mode button (displayed in top right corner, unless disabled in the options) and focus strike the glowing red weak point. It will play a unique animation, coupled with big damage.



A monster can be captured, once it's health has been reduced to something like 10~20%. Most will start to limp in a very obvious fashion, and a small skull gets displayed next to their icons on the mini map.
At that point, lure them into a shock- or pitfall trap, and hit it with TWO tranquilizer bombs or -bowgun ammunitions.
To craft a trap, you'll need to buy a "Trap Tool" at the base camp item vendor. All other ingredients must be gathered in the wilds:

• 

• 

You can find your amount of hunted monsters in the menu -> Info -> Large Monster Field Guide.
Note though that the "Hunted" counter does already include the captured monsters.
For the screenshot just above, I've captured the monster 4 times, and only slayed another 2, which aren't displayed. So that monster only provides 6, and NOT 10, monsters hunted towards the 3 achievements.

Tempered monsters will become available during chapter 4 and simply refer to buffed up versions of normal monsters, outlined in purple on the minimap and quest target icons. Not to be confused with Frenzied monsters, which do NOT count toward this achievement.

Apex monsters are lore related and refer specifically to:

• Rey Dau
  
• Uth Duna
  
• Nu Udra
  
• Jin Dahaad

Just about self-explanatory.
Your Palico will follow you per default, unless you specifically disabled it from doing so at camp.
It will also withdraw, once there's 3 or 4 hunters in a multiplayer or SOS signaled quest.



You need to have 1,000,000 zenny on hand, all at once.
This one is basically guaranteed along the way to all other achievements, especially if you just sell some stuff you have in abundance at the end.

You can grind this relatively effectively in more or less an hour though.
Find the camp hidden behind the waterfall in area 8 of the Scarlet Forest. Right next to the camp is a fishing spot, with a second one hidden behind a dive in that same cave.
These two spots spawn up to a dozen Golden- / Platinum Fish rather regularly, which drop their scales on getting captured with the Capture Net. These sell for 1,000 (gold) / 2,000 (platinum) zenny a piece. With up to 3 scales on a single fish, that's an easy 6,000 zenny. So a rough estimate of ~50,000 zenny in total for ~2 minutes of fish capturing per visit.
Just do a quick trip after each quest, or spam rest in the pop-up camp, or just fast travel to a different map and return a minute later.

Craft weapons and armor pieces from late game materials. Upgrading through the tree works.
Haven't tested, if rarity 7+ artian weapons (for the achievement just below) work for this.

• 

More weapon crafting. You'll unlock artian weapons during chapter 4, where the game will take over further explanations upon talking to Gemma. For rarity 8 materials, you'll need to hunt the tempered versions of the monsters with rarity 7 armor pieces.



"Special items" are intended exclusively for trade with NPCs and can usually be obtained at gathering spots marked with this icon ->

Let's start with the 2 exceptions.
The first one is the "Large Goldenscale Vase". While inifinitely obtainable through the "Remarkable Relic Emergence", like the items further below, it's also a guaranteed reward for completing Alma's side mission. In order to unlock that mission, you need to have encountered a Blangonga on a field trip through the High-Rank Cliffs.

The second is is the "Wyvernsprout". Thanks to saebias for telling me about this item in the comments:

"Wyvernsprout" is a parasitic fungus that can grow out of herbivores that have been slain. I can confirm I got this to happen with Ceratonoth during the Fallow, but it may work with all herbivores in different seasons too. I have not been able to get it to grow from Large Monsters, so it may just be herbivores.

Any carcasses of a Ceratonoth (and likely other small monsters) may get covered in a white mold and grow the rare "Carrion Mushroom" gathering spot, which drops the Wyvernsprout:

• 

The remaining 9 are found at rare gathering spots.
At chapter 4, you'll unlock an extensive "Environment Overview". Within that overview, you need to check for the "Emergence" notifications, as the final 6 special items will only be available in those specific timeframes.

• 

Once one of the Emergence events is active, fast travel to that region, open your map and navigate to the "Filter icons" option. Further put the filter on "Gathering", mark the gathering spots mentioned below and have your Seikret carry you to the exact location.

• Special Item

  Emergence

  Gathering Spot

  Location

  Nightflower Pollen

       none

  Ephemeral Blossom

  Plains, Forest (full moon*)

  Queensbloom Pollen

       none

  Queen Rafflesia

  Forest (during "Plenty")

  Time-honed Wylk Gem

            --->>

  Wylky Crystal Outcrop

  Plains (always)

   

   

   

   

  Emergence required:

  Great Windward Aloe

  <<---

  Great Windward Succulent

  Plains

  Thundering Fulgurite

  <<---

  Fulgurite Vein

  Plains

  Genesis Opal

            --->>

  Magnificent Fossil

  Plains, Basin, Wyveria

  Bulky Treasure

            --->>

  Bountiful Treasure

  Forest

  Eternal Scarlet Amber

            --->>

  Colossal Amber

  Forest

  Antimite Mass

            --->>

  Giant Hopper Crystal

  Basin

*Regarding Nightflower Pollen, thanks to svolder and Froggy for pointing out the full moon requirement, as well as QualitY for these more thorough instructions:

Nightflower pollen can only be obtained during a full moon. On the night that the full moon will appear, rest into evening, not nighttime. If you rest right into nighttime it will not appear, you must rest into evening and let the full moon rise naturally to make the nightflower appear.

The search for these items can be sped up significantly by resting in your tent or through the BBQ grill, as that rerolls the environment. Though I also recommend checking the environment overview upon joining other people's field surveys and investigations through SOS signals, as these quests have entirely different environments from yours.

You can check your currently owned special items by entering your camp, clicking View / Sell Items and navigating to the rightmost tab for "Special Items / Other".
There you'll find your trade-in materials, meal ingredients, and lastly special items.
Also, as has been pointed by KPuddi in the comments:

The 10 special rarity 6 items will show x0 in your stash if you have had them before.

Use the BBQ Grill from your item bar (unless disabled in camp) and you're gonna have to choose between:

- " Grill a meal ": Uses a Ration from within your chest and will always unlock the achievement.

- " Grill meat ": Uses a Raw Meat from your inventory / field pouch and requires you to complete the ensuing minigame successfully.
Press the confirm button when the meat looks nice and tasty ->
Then slice it in rhythm to the soundtrack.



Specifically travel around the edges of the maps and suitable spots will be pointed out to you:

• 

Enter your tent, navigate to the Appearance Menu and choose to customize your Seikret.
Only available after the first handful of assignments.

• 

Side Missions refer specifically to NPC requests and are not to be confused with Alma's Optional Quests. The vast majority of these unlock during chapter 4.
You can find a list of all your currently available side missions in menu -> Missions & Quests tab -> Mission Info.



Go to the base camp in the forest map and talk to Kanya, the NPC illustrated in the screenshot for the achievement just above. She has a questline of 5 side missions about fishing.
Once you've done so, approach a suitable fishing spot (like the one just to her left), and the game will throw a number of tutorials about this minigame on your screen.
The Goldenfish for mission #2 can be found easily in the cave behind the waterfall of area 8 in the forest.
The Gravid Bowfin for mission #3 can be found to Kanya's right during the "Plenty" period.
The whoppers are her 4th mission and explained once accepted, alongside giving you the required bait.
The giant squid is one such whopper and can be found in Scarlet Forest - Area 17.

Here's a more thorough steam guide about everything related to fishing:

• https://gtm.steamproxy.vip/sharedfiles/filedetails/?id=3438935955

Capture 2 of the rare endemic life by launching your Capture Net at them from your item bar (unless disabled at camp).
If you've played World or Rise, you'll know what these are about.

The shooting star one is located in the Windward Plains - Area 11 at night.
So far, I found it immediately next to these 2 gathering spots ->
Big thanks to Toruma for this tip in the comments:

Get some screamer pods and fire at it. It'll make it easier to catch and prevent it from running.

Look for a Baunos flying around near the spots in the screenshot, focus mode them and grab the "Echo Feathers" with your grappling hook, which will equip Screamer Pods to your Slinger.

The wyvern coin one can be found in multiple locations across all maps, almost always in tight and narrow dead ends of somewhat hidden areas; many of them near safe camps.
Alma will point them out to you by asking: "Is that creature holding something?".
If you loot an "Ancient Wyvern Coin", you've found one of the many locations this fella can spawn.

Simply use your binoculars from the item bar (unless disabled in camp) and you'll be informed about their gold crown eligibility.

Alpha Doshagumas will always be of gold crown size. Either find one in the field, or join the early main story assignment "Pinnacle of the Pack" via SOS signal.




Monsters come in slightly different sizes. Something like 80%~120% of the "normal" size you're gonna see most of the time. The size is completely random. Once you're going for the gold crown grind, make sure to use the binoculars to check their crown eligibility - see the achievement just above.

Note that you can use binocular confirmation to save gold crown monsters as investigations for later hunts (once unlocked during chapter 4), as the gold-worthy size will be saved to the investigation as well.
This allows you to share it with others, should you wish to do so.
And as has been pointed helpfully by Ares in the comments:

You can save investigations after you killed a monster aswell. This is especially useful when you forgot to save a gold crown monster investigation.

Talk to Alma -> Field Survey History -> Save Investigation

"Many" means every monster available on launch, hunted once each. So everything except these title update monsters:

• TU 1: Mizutsune
  
• TU 2: Lagiacrus, Seregios

Since not all monsters can vary in size, the following monsters are also excluded from the "many" for gold crowns:

• Guardian Arkveld
  
• Jin Dahaad
  
• Zoh Shia

If you're new to the franchise: consider holding off on these achievements for a while. Capcom always releases post-launch event quests with massively boosted, sometimes guaranteed gold crown chances.
This grind can turn into a huge waste of time without those event quests.

And yes, capturing a monster DOES count towards crown sizes.

Join a "Recommended Lobby". It's gonna have enough people to get these two right away.
Open the menu, go to the "Communication" tab and open the "Member List".
Navigate to the "Lobby Members" and click on another player.
Choose "Follow" for the first achievement, then choose "View Hunter Profile" on that person and another 29 folks for the second.



Finishing a quest exclusively with SOS signal summoned Support Hunters doesn't work.
You actually gonna have to hunt together with other people in multiplayer. It is NOT required to fill all 4 party slots with other people. Just 1 other person suffices.

Joining mid-quest via SOS Flares or lobby / link member quests in a public lobby DOES count, regardless of whether you hosted the quest yourself or joined someone else's. As long as there's another player in the quest at the moment of completing the quest's objective, that's a multiplayer completion.
It also counts across all quest types: assignments, optional- & event quests, field surveys, investigations.

And if you want a full deep-dive into multiplayer, refer to this steam guide:

• https://gtm.steamproxy.vip/sharedfiles/filedetails/?id=3435493455

Thanks to everyone for providing helpful tips, tricks and other information in the comments!
This includes:

• Thanks to saebias for telling me about the existence of the "Wyvernsprout"
  
• Thanks to svolder, Froggy & QualitY for their information about the Nightflower Pollen
  
• Thanks to KPuddi for the info about previously owned rarity 6 special items
  
• Thanks to Toruma for the tip about screamer pods' effect on the shooting star endemic life
  
• Thanks to Ares for the tip about using the Field Survey History to share gold crowns

And since we're here, thanks to Daniel7400 for providing an achievement progression tracking mod over at Nexusmods:

• https://www.nexusmods.com/monsterhunterwilds/mods/721

Haven't tested it myself, but has been pointed out to me in the comments and does seem helpful.