Words on trousers or shorts that land on the butt. This includes sports uniforms. Just looks goofy.
Pajama pants. Oh, get dressed to go out! Goes for slippers too. Only excused if you are going to the ER.
The ongoing saggy pants thing. Really. Thankfully, such baggy clothing makes bad guys easier for cops to catch. On the other hand, it's harder to search baggy clothing with many pockets. Oh, and your underwear? There's a reason it's called underwear!
Inappropriate clothing for the weather. Shorts especially. Cars do occasionally break down, and if it is 40 degrees or below, inadequate clothing can be life threatening. As in, wearing shorts can help make you dead.
Stupid premade fades and wrinkles on blue jeans. I'll fade my own stuff, thanks. Cheaper too, as most of this is in "high fashion" jeans that cost hundreds of dollars.
Too much eye make up on women. If you have your eyes clearly outlined, that's too much. If it looks like someone mugged you, that's way too much.
Bra straps showing from underneath tank or spaghetti strap tops. See underwear, defined.
Muffin tops. This results from clothing that is not fitted properly. Your waist band should not be pushing rolls of fat upward. It is possible to have clothing fit correctly! Close cousin of this problem: trunk fat rolls from wearing the wrong size bra. Listen, I am "of size" but I refuse to highlight my rolls. I want my clothing to fit but not be tight and not emphasize my roll-y defects!
Dressing inappropriately for age. Kids should dress like kids. Teens like teens. Adults like adults. Anyone over 50 needs to stay out of Juniors, generally speaking. Teens need supervision, but should be allowed out of the middle school section.
Fat guys wearing their trousers below their gut. This just cracks me up whenever I see it. Waist size of pants: 36 Actual waist size: 46 Denial is a very strong thing...oh, that reminds me: balding guys should avoid the comb-over. It just doesn't work, especially in the wind. It was a great moment in my family's history when a hair stylist talked my dad out of his comb-over sometime in the mid to late 1970s.
And finally (although I am sure I'll think of something else later--readers should feel free to add their own peeves), rolling the elastic waist band on warm up/sweat pants/shorts so that the unfinished side and the label stick out!
Nothing world shattering here, just the sandpaper of everyday life...