Seems like half of the posts here are no-nos for other people, but the other half (and the OP) are for one’s self. So… I’ve got a lot of personal no-nos.
For pants: I don’t wear shorts. Period. I got tired of being told I had bony knees and/or people mocking my paleness. I rarely wear jeans; they’re too bulky and uncomfortable until well-broken-in, and I don’t wear my few pairs often enough to make them comfy. Cargos are okay only for work or chores, otherwise I’ll be wearing chinos or better if I can manage it. And, no pleated fronts on anything.
I’m really picky with shirts. No Polo shirts (reminds me of working fast food), no club shirts, no casual button-up shirts, no short-sleeve dress shirts, no button-down collars. I prefer shirts without chest pockets, really prefer fitted dress shirts (non-fitted are fine if I’m wearing a jacket). A neutral or coordinated t-shirt is a must with any shirt. T-shirts should be of normal length and size, fitted is nice… those giant t-shirts that look like draped dresses won’t work.
No sweaters, no sweatshirts or sweatpants, track pants are reserved only for actual working-out, no sandals/flip-flops, no Crocs. Casual/athletic shoes must not be overly-padded “foot pillow” type sneakers. Dress shoes should be oxfords or similar, with no decorative stitching or holes.
Now that it’s cold, I’m once again alone among coworkers for breaking out a wool overcoat and scarf. I can’t wear those puffy synthetic-fiber jackets that make “shoop!” sounds when you swing your arms.
Accessories/et cetera: a plain, non-gaudy watch; a plain, non-gaudy leather belt, and black-frame glasses. Nothing else (except a wedding ring if I ever get married again). I would refuse to wear a Bluetooth earpiece, and long ago removed my ear and tongue piercings. No tattoos at all; I like the fact that I’m seemingly a rarity, a youngish thirty-something with unmarked skin.
And, for all clothes and accessories: I won’t wear light colors. No pastels, and if I wear red it’s going to be scarlet; blue, it’ll be navy. Every ex of mine has sworn that they’d get me to start wearing bright or light colors, then they see how sick I look with those colors on. I look great in darker shades, though, and can look just flashy in maroon or magenta.
Overall: I’d rather be too dressed up than too dressed down, so my wardrobe tends to reflect this; lots of dress clothes, few casual clothes. And this is all a 180 from where I was a decade ago.