Sometimes I cross traits. To name one example, my Eileen has stubborness, idealism and a sense of honour as her chief quallties. How easily led are your characters? Eileen isn't, she's the one doing the leading. And therefore likely to clash with anyone else who thinks they should be the leader.
So what traits would you use to build your characters? (Bear in mind all characters need to have thier positive and negative qualities). How did they develop these traits? How would the nature versus debate work out for them?