I like to make something that's in keeping with the game's theme. Usually I try to avoid making overly TALL characters, though I often, if given the choice, make them short versions of whatever they are.
I hated the customization in Age of Conan so very much (well that and a lot of the game, really) because I felt like making my Assassin a short, thin, wiry guy that just sort of hinted at muscles. Not fat, not muscled, just... "easily overlooked", something I'd picture was ideal in an Assassin. Yeah, fat chance. There was no way of making something that didn't look like it regularly does two hundred and fifty pull-ups before breakfast.
For some reason, the lack of real options in... say... WAR and WoW both, never really bothered me. I could always find a look there that I liked, and their lack of body sliders never bothered me. But when you SUPPLY such sliders, make them have a fugging EFFECT on your toon, OK?
Best char customization EVER was City of Heroes/Villains. There has never been greater character customization ever. I never enjoyed the game at all, but making characters was HYSTERICAL. I made SO MANY of the blighters...