To be honest, I'm no character designer (like I could never draw adopts or smth I think), I'm more of a writer type, where I have a set of characters inside some story, and I come up with the designs only after their story is set enough inside itself so that I can draw some scenes with them - so I often don't design for the sake of designing and visuals, it often mostly depends on the story and context and I can go real different directions!

However when I do get some freedom for their appearance, I mostly reference stuff: I look at models, influencers, and just people I see around irl and try to find cool things I can steal for my designs :DD Like cool facial features? Someone's attachment to certain color in their style? Overall vibes? Stuff like that

It's important to me that my characters' faces are different (tho my style do be swiping it away the moment I try to go just a bit less realistic- yeehaw I hate that ;w; ) so sometimes I add features that people might find strange when in not-so-realistic artstyle; like Kayleigh's wide mouth, Edel's corners of the eyes, Constans' large jaw... Tbh that's my favorite part, to create something like this, realistic but somewhat unique to the character?

I'm not sure if this rent answers the question or not really (in the end I reread it and maybe I misunderstood- sorry), but I hope yall understand my line of thinking about character designs! :D
Ty for asking! ❤