What you need:
Step 1: Step 1
just make sure that :
-it's a square
-its side is at least twice as long as the pictures longest side.
You can even use two sheets of paper of a different colour, just put one on top of the other!
Start by folding the square in half in both directions.
Step 2: Step 2
Step 5: Step 5
Glue three out of four sides. The fourth will make your frame stand up. If your paper is too weak to hold the frame, glue a paperclip to stabelize it (as shown).