Cotton element is not used often in Little Alchemy 2, but it is needed to combine Thread, which is necessary for Fabric and Armor. Making Cotton is not easy, you have to combine Life, Plant, and Cloud first. We have figured out the easiest way to make Cotton, check out the detailed walkthrough and try it yourself.
Fire + Earth = Lava
Lava + Earth = Volcano
Water + Water = Puddle
Water + Puddle = Pond
Water + Pond = Lake
Lake + Lake = Sea
Earth + Sea = Primordial Soup
Volcano + Primordial Soup = Life
Earth + Life = Soil
Life + Soil = Plant
Earth + Earth = Land
Earth + Land = Continent
Continent + Continent = Planet
Air + Planet = Atmosphere
Water + Atmosphere = Cloud
Cloud + Plant = Cotton