I helped my niece (age 16) redecorate her room on a Saturday afternoon a few months ago. (Yes, we did this in ONE day!) We began by choosing new bedding at Kohl's, and visiting the paint store for matching wall colors. We found some circle stencils and more matching paint at Hobby Lobby. We also found some little circle mirrors in various sizes. It's hard to tell in the photo, but some of the circles are actually those mirrors. We had fun painting together all afternoon, and she was pleased with the result.
I'm planning on doing this same "circle" theme in my daughter's room soon. Why not re-use the stencils I purchased? Stay tuned for those pictures!