In my opinion, lengthy posts tend to be better because we need to know a character's thoughts, feelings, and motivations. "Show, don't tell" is important, but in role plays, I think that it's nigh impossible to have a decent character shown only through action. Give me the "why." Give me some...
Ooh, this sounds interesting! Fun to see where people start.
My first ever character, if I am remembering correctly, was a chick named Ria. I don't remember much about her, only that she had red hair and younger sister named Lotta. I'm pretty sure I played her really, really inconsistently...