One thing I've always liked doing is making playists for my various characters, and when other people have theirs available, I like giving them a listen too, to see what kind of character vibes the author is trying to give, or the sort of personality they imagine from their character that might not be present in the text just yet.
I've made playlists for four of my comic's six mains, still got two more to go. But I kind of approached it with stuff that was A) thematic to the character and B) stuff that I think would fit their personal taste.
I'd love to see what you guys have made! And feel free to drop a link to your thing, too!
