Belts complete an outfit. They are essentially that je ne sais quoi that an outfit can do fine without, but just really desperately instinctually craves.
Belts need intuition. I love writing rules when it comes to fashion, but the truth is that belts just don't follow any. I've been studying belts for a long time, and I have finally come to the conclusion that the final decision - to belt or not to belt - can only be made in the moment, on an impulse, driven by primal instinct.
Belts that give shape:
I remember as a girl I used to wear dresses that had a bow at the back. Now that bow has been replaced by bold, chunky belts that flatter the figure.
Lanvin's AW09 loves thin belts on dresses that are already quite figure-ready without them. This works because the colour of the outfit is pretty constant and basic - the belt just gives it an edge, makes it interesting.
This dress by YSL is classy, and the belt adds that raw, urban touch to it. Definitely my style :)
Similar concept, though I'm not sure who its by:
This one's worn hers over her cardigan. Not something I'd think of doing myself - this probably works best on leaner figures.