Recycling is even involved. A double WIN.
Wash out your old peanut butter and jelly jars (this might make you start shopping for food based on the container it is in) and peal off the labels by giving them a soak in soapy water. You can get off any additional residue with a razor blade.
Print pictures off and pop them in. The picture should curve with the glass. No right or wrong way to do this but if you are a person who likes instructions, go here.