Hit V to open the crafting interface. Recipies are displayed below the crafting interface, segregated by type. To craft items, you need one, two, or three ingredients and depending on the type of item, a crafting station or one of the crafting masters from Azuria. Crafting a rock hammer requires no special skills. Abilities, spells, armour, and other items are crafted the same way. Pay attention to the recipes and you can't get lost.