We all have a personal taste, is there some clothes, looks, characteristics that you don't like in character design?
-Big jewels, especially the magical girl type of jewels all over the designs.
-When the clothes have lots of random belts, zippers, etc, just to make the designs more "interesting".
-The "bikini" armor worn by female warriors. Unless everyone if fighting in a silver thong, I don't see why would any warrior thin this is such great protection.
-A black haired character having purple strands to show that the character is such a rebel!
-extremely narrow waists. I'm not very fond of hourglass figures. I don't love the Disney princess/classic Barbie shape. I also don't particularly like when artists draw chubby girls and call them "realistic" but give them impossibly narrow waists. I used to draw narrow waists and nowadays I prefer "pear shapes".
-The generic, plain, normal schoolboy designs in the harem animes. There is literally no effort put into this type of character because viewers are supposed to insert themselves in his place...I get it.
I'm not saying that those traits don't suit the characters or that they can't look great depending on the artist and there are always exceptions -.