I use my girls for creative development of the characters in my book, much the same way that you are using them for the creative focus of your movie.

In my book, the girls all go to the same school. That's how they know each other and the basis on how they communicate with each other. The girls who are best friends share similar interests or similar attitudes. For instance, I have a cheerleader and a ballet dancer who are snotty, and I have two rival cooks who end up being best friends...most of the time, and three girls who are into horseback riding and swimming alternately, except one who is in to both, another talented ballet dancer and gymnast who are outgoing, fun, and friendly, and the shy nice girl. I also have two boys....one is an annoying jock nerd, and the other is a quiet sweet type.

It's so much fun imagineering, but sometimes, it takes me half a day just to dress them all!