Kind of like old WoW. A more direct approach on crafting. Each player can only have 2 professions, and can harvest items from the world & mobs to create items specific to their profession. Professions have their own leveling system and you can make greater items as you progress.
Back to 2 professions, the ones you choose will be beneficial to the other one. For example, a player could choose from:
Having mining and blacksmithing would make a great combo, and herbalism/alchemy would be a great combo as well.