I had a friend ask what we were planning to wear to an upcoming fetish party, as they had never been to one before. In years past I might have gone in full perv regalia (such as head-to-toe latex), but since we were going with a few of our "non-freaky" friends I had to come up with something that wouldn't scare them (or the neighbors). I ended up doing some sketches to show her what people might typically wear to a fetish club.
Generally, if you're a girl (or cross-dressing boy), it's your chance to unleash your inner call girl. I'm seeing body-bearing top and bottom in some shiny material, with maybe a waist-cincher and garter belt. Fishnet stockings, with long gloves and tall platform boots would be appropriate too, accessorized with a collar, wings and a magic wand if at all possible.
For guys, I think it's a little harder, and all I could come up with was a emo-boy look, or the traditional leather daddy. I'm probably the worst person to ask about this sort of thing... Is there some other option for guys who want to get into the spirit, but not be cross-dressed or like the gimp from pulp fiction (not that there's anything wrong with those things!).... or even worse: street clothes!