Can also be used as an envelope for carrying items securely.
It's disposable, recyclable, sustainable, environmentally friendly plus widely and freely available.
Step 1: Making a paper square from a rectangular sheet
You are going to use basic paper folding techniques to crop it square.
Use your finger/thumb nails to form sharp, straight creases. If your nails are too short, use the edge of something like a credit card or a plastic ruler.