All you need is a piece of paper. Fold it in half long ways.
Step 1: Fold the Corners in to the Center
Fold the corners in to the center
Step 2: Fold the Triangle Down
Fold the triangle down along the middle crease line.
Step 3: Fold the Top Corners Down
Fold the top corners down to the middle with a little more room on the bottom.
Step 4: Fold the Small Triangle Up
Fold the small triangle up to the center crease line.
Step 5: Fold in Half
Fold in half
Step 6: Fold Each Side Down
Fold each side down