Crafting stations are upgraded with their respective station upgrades. More unlock as you continue through the game and acquire new resources.

Thanks a lot. So let's look for new ressources :)
Maybe next upgrade might come with killing the deers, who knows.

if you haven't picked up flint, be sure to do so.

Pick up at least one of everything. And craft one of everything too... some recipes are only unlocked when you craft other recipes. No spoilers, though. :)