Take your piece of paper...

And fold the corner up.

Take the top rectangle of. It should look like a triangle.

Unfold and fold it the opposite way. It should look like a triangle with a crease in the middle.

Unfold and fold into a rectangle. It should look like a rectangle with a triangle in the middle.

Unfold and fold opposite way.

Fold one corner up to the top corner.

Repeat.

Fold that middle corner into the center.

Repeat.

Fold top corner into the flap.

Repeat.

Flip.

Dis is wat it should luk like

Hole at da bottom

After I've blown it up!

Bloopers!