Which profession is the most profitable?

I'm thinking of trying to earn myself some money in game so i can actually buy things and I've heard that the profession system is a way to do this.

Which profession(s) would be the most profitable? Should i do Herbalism and Alchemy for materials,potions and fusing or Mining and Smithing?

Also within these professions, what would be the best way to get items through fusing (what should I fuse?) and what kind of Materials should I be looking for to sell?

Thanks!