Get yourself some cheap paper. I used red because the house colors will be (mostly) warm colors so that they'll pop off of that cool academic background. Just tear (or cut) your paper into some shapes and sizes and play with them like puzzle pieces until they begin to feel right.
A fun game to play is to cut random pieces of black construction paper out and lay them on white paper. Move them around and as they feel "right", take a quick photo. Then play with them some more, taking photos as you go.
Super little book on composition: Picture This by Molly Bang (and at $3.65 used, it's a good addition to your library). Molly is a children's book author/illustrator. Her pictures are deceptively simple.
Happy Friday to all of you. Enjoy your weekend.