In general every new sticker is result of the combination of two others.
The exception are wild stickers which will appear under certain circumstances and can be turned into stickers using the Stickerizer.
The game uses your computers clock to change between night and day mode and no online time, so changing your personal settings allows you to get the time you need without waiting.

Use STRG + F with the guide open to quickly find the recipies you are searching for.

Playing the tutorial gives you the four elements.
Water, Fire, Air and Soil. In addition you will get the Stickerizer.

Water + Water = Lake
Water + Lake = Sea
Water + Sea = Ocean
Tool + Lake = Fishing Rod
Lake + Fisching Rod = Fish
FIsh + Fire = =Fried Fish=
Water + Fire = Energy
Water + Soil = Mud
Water + Mud = Swamp
Swamp + Energy = Life
Life + Fire = =Fire Spirit=
Life + Soil = =Soil Spirit=
Life + Stone = =Golem=
Life + Sand = =Sandman=
Life + Wind = =Wind Spirit=
Life + Water = Animal
Animal + Swamp = Frog
Animal + Moon = Wolf
Life + Animal = Human
Human + Fish = =Mermaid=
Human + Cyclops = Pirate
Human + Wolf = =Werewolf=
Human + Cave = Caveman
Human + Potion Growth = =Giant=
Sun + Human = =Sun Person=
Water + Air = Steam
Steam + Air = Cloud
Cloud + Water = =Rain=
Cloud + Air = Sky
Sky + Fire = Sun
Sun + Soil = Plant
Soil + Plant = Grass
Grass + Soil = Meadow
Plant + Meadow = Flower
Flower + Human = Woman
Meadow + Sun = Savanna
Savanna + Animal = Lion
Lion + Human = =Sphinx=
Meadow + Animal = Bull
Human + Bull = =Minotaur=
Bull + Knife = Leather
Leather + Air = Ball
Ball + Human = Game
Ball + Game = Football
Bull + Fire = =Meat=
Grass + Water = Potion Shrink or Potion Growth (probably depending on night and day)
Potion Shrink + Mirror = Potion Growth
Potion Growth + Mirror = Potion Shrink
Potion Shrink + Human = =Dwarf=
Potion Shrink + Woman = Fairy
Plant + Tool = Wheat
Wheat + Sun = Straw
Grass + Grass = Bush
Bush + Bush = Tree
Tree + Tree = Forest
Caveman + Forest = Monkey
Monkey + Tree = =Banana=
Monkey + Clothes = =Suited Mokey=
Monkey + Horns = =Horned Monkey=
Human + Tree = =Ent=
Bush + Tool = =Berries=
Woman + Forest = =Mavka=
Animal + Forest = Bear
Sun + Grass = Straw
Fire + Soil = Lava
Lava + Water = Stone
Plant + Stone = Paint
Ball + Paint = =Wilson=
Paint + Paper = Painting
Painting + Life = Movie
Manga + Movie = =Anime=
Human + Stone = Statue
Stone + Wheat = Flour
Flour + Water = Dough
Dough + Fire = Bread
Bread + Game = =I am Bread=
Stone + Water = Sand
Sand + Swamp = Clay
Clay + Life = Man
Man + Mirror = Woman
Sand + Sand = Desert
Desert + Animal = Snake
Woman + Snake = =Medusa=
Snake + Tool = =Poison=
Sand + Water = Beach
Beach + Tree = Palm
Sand + Fire = Glass
Stone + Stone = Mountain
Stone + Fire = Metal
Stick + Metal = =Spear=
Fish + Metal = =Canned Fish=
Stone + Metal = Tool
Metal + Energy = Electricity
Air + Electricity = =Lightning=
Mountain + Water = Cave
Soil + Soil = Pressure
Air + Air = Wind
Mountain + Wind = Cold
Cold + Water = =Ice=
Cold + Animal = =Polar Bear=
Mud + Wind = Dust
Dust + Fire = Powder
Powder + Fire = Explosion
Powder + Explosion = Dynamite
Dynamite + Lake = 4 Rare Fish
Wind + Sand = =Sandstorm=
Wind + Ocean = Storm
Water + Energy = =Water Spirit=
Sheep + Tool = Wool
Sheep + Fire = =Meat=
Wool + Tool = Thread
Thread + Thread = Fabric
Fabric + Human = Mummy
Sheep + Stone = Bone
Bone + Soil = Dinosaur
Dinosaur + Fire = =Dragon=
Bone + Bone = Skeleton
Skeleton + Life = =Undead=
Bone + Stone = Knife
Knife + Tree = Stick
Paper + Stick = Wings
Wings + Goat = =Winged Goat=
Wings + Human = Angel
Angel + Evil = =Demon=
Animal + Wings = Bird
Mountain + Bird = =Eagle=
Bird + Beach = =Seagull=
Bird + Electricity = Plane
Plane + Explosion = =Parachute=
Bird + Bird = Egg
Egg + Sand = Turtle
Turtle + Frog = =Cappa=
Animal + Stick = Horns
Animal + Horns = Goat
Goat + Game = =Goat Simulator=
Goat + Human = Faun
Stick + Fire = Bonfire
Stick + Stone = Axe
Axe + Palm = Wood
Axe + Tree = Wood
Wood + Pressure = Paper
Paper + Paper = Book
Wood + Tool = Wheel
Wheel + Wood = Wagon
Wagon + Energy = Car
Car + Game = Racing
Racing + Animal = Horse
Horse + Human = =Centaur=
Water + Wood = Raft
Raft + Wood = Boat
Boat + Boat = Ship
Ship + Storm = =Shipwreck=
Wood + Straw = =Bed=
Wood + Stone = Hammer
Hammer + Stone = Ore
Ore + Ore = Ore Deposit
Stick + Ore = Pickaxe
Ore Deposit + Pickaxe = Copper Vein or Silver Vein or Iron Deposit or Metal X Deposit or Gold Vein
Metal X Deposit + Pickaxe = =Metal X=
Gold Vein + Pickaxe = =Gold=
Silver Vein + Pickaxe = Silver
Silver + Glass = Mirror
Iron Deposit + Pickaxe = =Iron=
Copper Vein + Pickaxe = =Copper=
Ore + Tool = Workbench
Workbench + Tree = Log
Log + Log = Cabin
Wounded Wolf + Cabin = Good
Good + Mirror = Evil
Bird + Evil = Bat
Bat + Human = =Vampire=
Good + Evil = Black X White
Black X White + Paper = =QR Code=
Bear + Black X White = =Panda=
Animal + Black X White = =Zebra=
Tree + Black X White = Birch
Birch + Tool = Resin
Resin + Stick = =Torch=
Evil + Faun = =Ochokochi=
Cabin + Cabin = =Village=
Cabin + Mummy = =Pyramid=
Wolf + Cabin = =Dog=
Wolf + Woman = =Dog=
Wolf + Man = =Dog=
Cabin + Animal = Kitty
Kitty + Woman = Neko Girl
Neko Girl + Paper = Manga
Workbench + Metal = Weapon
Weapon + Powder = =Musket=
Weapon + Metal = =Sword=
Weapon + Human = Warrior
Game + Warrior = RPG
Warrior + Warrior = Squad
Squad + Squad = Army
Army + Army = =Blood=
Army + Squad = =Blood=
Knife + Fish = Fishbone
Knife + Fishbone = Needle
Needle + Fabric = Clothes
Lava + Pressure = Volcano
Volcano + Sea = Island
Volcano + Ocean = Island
Bird + Island = =Parrot=
Pirate + Island = =Chest=
Island + Sun = Japan
Japan + RPG = jRPG
Island + Island = Mainland
Mainland + Ocean = Planet
Planet + Sun = Solar System
Solar System + Solar System = Galaxy
Game + Galaxy = =Space Sim=
Galaxy + Galaxy = Universe
Human + Octopus = =Cthulhu=

The Wounded Wolf will appear when you open the hinttab. Combine it with the Cabine and you will earn the Good sticker.

To get the [wild]Sheep you need to place muliple pieces of grass in your crafting tab and then combine two of them. It will make the sheep appear. Just use your Stickerizer on it and you will have it ready to craft.

The [wild]Moon appears at real-time night. For me it was 7 pm when it appeared.

I just got it while writing this guide. One minute idle seems to be enough to make it appear.

The Cyclops appears when you got rare fish and mountains in your crafting tab. I recommend putting a lot of rare fish in since he eats them. So you would have more time to catch.

You need to put beach and palm on your crafting tab and it will appear almost instantly.

The Octopus appears when you got at least one Ocean and like four or five fish in your crafting tab.

You need to put five statues in your crafting tab. The QR-Code ingame leads to a website with a screenshot of this. That way we discovered it. http://eikosol.com/sc/qr/
This screenshot also shows that you need to be in nightmode to be able to unlock it.

You need at least the secret sticker and the island sticker. I heard of it working while adding 5 statues, maybe there just need to be just any other stickers around.

Angel
Animal
Anime
Army
Axe
Ball
Banana
Bat
Beach
Bear
Bed
Berries
Birch
Bird
Black X White
Blood
Boat
Bone
Bonfire
Book
Bread
Bull
Bush
Cabin
Canned Fish
Cappa
Car
Cave
Caveman
Centaur
Chest
Clay
Clothes
Cloud
Cold
Copper
Copper Vein
Cthulhu
Demon
Desert
Dinosaur
Dog
Dough
Dragon
Dust
Dwarf
Dynamite
Eagle
Egg
Electricity
Energy
Ent
Evil
Explosion
Fabric
Fairy
Faun
Fire Spirit
Fish
Fishbone
Fishing Rod
Flour
Flower
Football
Forest
Fried Fish
Frog
Galaxy
Game
Giant
Glass
Goat
Goat Simulator
Gold
Gold Vein
Golem
Good
Grass
Hammer
Horned Monkey
Horns
Horse
Human
I am Bread
Ice
Iron
Iron Deposit
Island
Japan
jRPG
Kitty
Knife
Lake
Lava
Leather
Life
Lightning
Lion
Log
Mainland
Man
Manga
Mavka
Meadow
Meat
Medusa
Mermaid
Metal
Metal X
Metal X Deposit
Minotaur
Mirror
Monkey
Mountain
Movie
Mud
Mummy
Musket
Needle
Neko Girl
Ocean
Ochokochi
Ore
Ore Deposit
Paint
Painting
Palm
Panda
Paper
Parachute
Parrot
Pickaxe
Pirate
Plane
Planet
Plant
Poison
Polar Bear
Potion Growth
Potion Shrink
Powder
Pressure
Pyramid
QR Code
Racing
Raft
Rain
4 Rare Fish
Resin
RPG
Sand
Sandman
Sandstorm
Savanna
Sea
Seagull
Ship
Shipwreck
Silver
Silver Vein
Skeleton
Sky
Snake
Soil Spirit
Solar System
Space Sim
Spear
Sphinx
Squad
Statue
Steam
Stick
Stone
Storm
Straw
Suited Mokey
Sun
Sun Person
Swamp
Sword
Thread
Tool
Torch
Tree
Turtle
Undead
Universe
Vampire
Village
Volcano
Wagon
Warrior
Water Spirit
Weapon
Werewolf
Wheat
Wheel
Wilson
Wind
Wind Spirit
Winged Goat
Wings
Wolf
Woman
Wood
Wool
Workbench
Zebra

Thanks to MakoSipper

You discovered a mistake?
You found combinations I havent included yet and want to share them without writing your own guide?
You got ideas what to change or add?

Feel free to tell in the comments, I will update this guide and hope to complete it with your help.

Thanks for the help to:
jpmaggers, NoAngelHonestly, KVNVBI, shpasic, Miraglyth, Tellah, nobody here but us trees, Flying Fox, Link3000XD, rho, Rozen, AngelKairy, Koryu, WINEEEEE, MakoSipper and BluePaw 🐾