For my project, I've dug out scraps of ribbon and patterned paper. I don't save every single snippet but if my paper is at least 2" square and my ribbon is at least a couple inches long, I try to save a few pieces here and there.
Punches make great use of those leftover paper scraps. I know you have lots and lots like I do.
I'm also using scraps of some old sheet music I bought at a garage sale. It's great stuff!