Step 1: Make a square
[Pic 1] Start with a regular sheet of paper. It doesn't matter how big it is, as long as it has right angles.
[Pic 2] Fold any angle up and across to make a triangle. match up the edges and crease. (The pencil shows the edge of the paper...it was hard to see in the lighting)
[Pic 3] Flip the whole thing over and fold the rectangle that's not included in the triangle back like shown.
[Pic 4] Now cut the fold you just made off. You can also rip it off if you know how to rip in a straight line like i did. You should end up with picture 4.
[Pic 5] You don't need the small rectangle, throw it away, keep it as a bookmark, or doodle on it.