DON'T wear skintight lycra or latex unless you think looking like a Black Pudding is sexually alluring.
DO use plenty of talc.
DON'T think wearing 5 inch platforms will disguise the fact that you are below average height. You will still look like a shortarse, just in really, really stupid shoes.
DO invest in a good corset. You can't go wrong.
DON'T wear a PVC sleeveless vest if you fall into the rotund category. You will look like a bowling ball. With chubby arms. Opt for a well tailored shirt instead, it is a far sexier look.
DO remember that just because you find a certain garment sexy it does not automatically follow that you will look sexy in that garment. A backless pair of PVC shorts may look great on the model on the website but very different when your hairy buttocks are protruding from them like a pair of Woolly Mammoth testicles.
DON'T wear ill fitting clothes just because it's fetishwear. It may be real leather and cost a month's wages but if it doesn't fit it won't do you any favours. If it is too tight (and yes, this is possible, even with kinkwear), too loose, too short in the leg or hangs off your body unflatteringly then change it for something that's right. The school nerd look is not generally a good one, even if that school nerd is wearing a shiny black tank top with matching trousers that barely skim his ankles.
DO get a second opinion.
DON'T wear your glasses over your latex hood.
DO let me know if I've missed anything.