Crafting
There are 3 main categories. Weapons, Clothing and Potions. Equipable items give permanent boost to skill, if equiped. Potions give effect like healing, or temporary skill boost.
If you have all required items to craft, images of item will be brighter.

Notable effects
Stealth potion - give you a chance to avoid unpleasant encounters.
It lowers chance to meet enemies on map.