Remember a childhood friend or enemy. What stood out as a trait unique to that child? Consider what has become of him or her based on that trait remaining true. I had a friend named Marsha for a short time in second grade. I say short because she did not let any of her friends have other friends. So I might imagine that she is busy now running the adult lives of her children since she probably lost her husband when he could not stand being smothered any longer. Or perhaps she translated her controlling ways into a successful Wall Street business but is now charged with insider trading. Pick someone you did not maintain contact with and haven’t heard about — that way you have plenty of room for imagining. You might want to change names for your character if you plan on publishing when you are done.