What's a good username?

maybe for a twitter or tumblr or youtube. idk. But Ive seen some really creative stuff like "totallytaylored"<< is this girl named taylor . or "imDEEgee" for this girl named dijah g. you know ... well my name is Marquita Johnson. I run track if that means anything. I'm kind of quiet and creative. lol idk. lemme know what you think. my current usernames are just like quita777 or broken_promisesz .. that's it.