Very low cost folded paper container, for holding small items (such as screws) during repair, assembly, construction etc.
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
Take a rectangular sheet of paper. In America this could come from a legal pad, or in Europe an A4 notepad.
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.