What you will need:
- A Piece of Paper; notebook paper, printer paper, etc.
This process can be cleaned up if you're a perfectionist; IE, making sure the folds/creases are crisp and the two corners, now folded triangles, perfectly align.
Which when folded correctly should look somewhat like an over sized envelope as seen in the illustration.
Please note that the fold may NOT be the prettiest but will nonetheless work.
Once more keep in mind, the fold's won't necessarily look crisp. Just get it as close and precise as possible.
Fold that triangle piece upwards and over the two corners; down the center.
The picture below should show this action mid-fold; IE not a complete fold yet just for the sake of demonstrating. Your's will be all the way folded and not popping up as high as the illustration.
I positioned the paper sideways to show the next folds a little better.