Well, you could cut out the largest circle first (with a wider diameter than needed, as the second will cover it anyway) and use the inside as the first. You'd still need to cut out the second one, but it'd save quite a bit of fabric. When making the skirt, just sew the largest circle a bit farther down than normal. I'm assuming that you'll be using a sort of tulle or something for added "fluff" here, so correct me if I'm wrong.
Saturday: Kotomi (Clannad)
Sunday: Fem!Watson (BBC Sherlock)
Han Solo (A New Hope)