Everyone is free to dress as they please. But since the OP asked...
1.Underwear is called
"under"wear for a reason. You wear it under your clothes.
2.Clothes have sizing for a reason. Wear your size, don't look like a potato sack or a muffin-top parade. And be conscious about length, please!
3.Make-up is to enhance a woman's beauty, not to make her - literally - look like a clown. It is make-up, not make-clown.
4.Everybody knows that tan is artificial... only you and the tan salon lady think it looks natural. Same goes for 2 inches long red acrylic nails.
5.They are called
"sun"glasses for a reason. Unless you have a medical condition, they are to be worn only when (surprise surprise!) it is sunny, and outside.
6.No baseball caps (especially backwards, nooooooo!
) outside sporting events, unless it is really sunny outside.
7.Too much bling is great on Christmas trees. You happen to be a person. It is just plain ugly and distasteful. Too much perfume will make you smell bad instead of good.
8. Do people really have to post signs "no shirt, no shoes, no service?" I mean, come on, it is a restaurant or a store, not your backyard. By the way, if I live near you, please be a dear and keep your shirt on even in your backyard. Or let me know and I will make sure I have a higher fence.
Those are the ones I remember right now, but I am sure there are 1000s of huge fashion faux pas.