Here's a simple way to fold a storage bag:
1. Take a rectangular piece of paper.
2. Fold the two shorter sides to the middle, leaving some overlap.
3. Glue the two folded sides together.
4. Fold the bottom up slightly.
5. Open the top layer of the folded part downwards, fold the open sides directly, and then fold the two sides to the middle again, again leaving some overlap.
