@Leyelle
I think this would be virtually impossible for me because I have so many interests, (and a lot of ethnic DNA being multi-ethnic) lol. Every character has at least one or two things in common with me even if they are nothing like me at first (visual) glance.
It's not about ethnicity so much as deliberately choosing models and inspirations that aren't myself. I'm trying to avoid making all my characters look alike and especially having them act alike.
Have you ever read a webcomic where all the characters more or less have the same basic personality? I sure have.
I have blue eyes, and a lot of my characters have blue eyes, but that's because the people I know who are inspiring those characters also have blue eyes, not because I have them! I just find that if I'm not drawing anyone in particular, then I'm likely to just draw myself more-or-less.