5. Squish the zig-zag shape together, and fold it as shown here. You can vary this angle to get different effects if you like. Crease it real good.

6. Now unfold the paper. It should look like the image on the left. Reverse the direction of the folds on one half of the sheet, and crease the paper to make it appear as shown on the right. This can be a little tricky, so take your time doing this.

7. Now compress the new folds. Apply a lot of pressure to make the folds hold nicely. Now you're almost done.