When we set WordPress Blogs up for the girls on our Network, we just send them over to WP and have them pick a Theme they like. Then we install it and do the header. Very simple and keeps the girls happy as they feel they have some input into design.
2 years ago, I grabbed a basic Blog Theme and threw that up for Carol with the intentions of redoing it properly. Well, 2 years later and I haven't touched it! Carol finally gave up on me