We used big brown paper and cut few piece (Same size) out, folded them and stapled them into a book. You can make your book any theme but this one for us was theme "Ramdon" lol
My son right now is into his shapes and abc's while my daughter is into animals. So one theme was not going to work.
Make sure when your kids are done you date them and save them so they can look back at what they liked as they grow.