Christiane Feser likes to crumple bits of paper, especially paper with faces on them. He is interested in how the photo changes and the surface of the paper.
You could apply this technique to your own photos when you are experimenting with your ideas – then draw from your own crumpled photos.
Always pay reference to new artists in your sketchbooks; it helps us to understanod where you got your ideas from and also show us that you are developing your ideas. Try not to get too many papercuts when folding!