I generally try to make my ocs look different from each other (emphasis on try, because I don't always succeed) but in terms of what kind of designs I like in fictional characters... if they have long white hair and even slightly blue eyes it is so over for me. this is my favorite kind of design and I predictably fall all over myself when one shows up. one just appeared in honkai: star rail and I am SO fucked. they don't necessarily have to have blue eyes, but blue eyes are what I see most often.

there are other color combinations I really like, though! blue and orange, mint and pastel pink, beach tones (pale yellow, white, seafoam green, azure, etc) ... I like seeing blue and purples together, and brown is my favorite color so I'm partial to brown/earthy palettes. I also really like darker-skinned designs with lighter hair! I'm trying to think of some of my favorite character designs so I can give some examples, mm... scarlita and bryon from afk journey; xueyi and firefly from hsr; roxie, steven stone, marley, palina, geeta, and rime from pokemon; ouni from children of the whales; firewatch, cantabile, and pramanix from arknights; sumika from yuri is my job ... maybe that's enough? haha