Start with a square, white side up.
Step 1. Fold one corner on top of the opposite corner.
Step 2. TOP LAYER ONLY: Fold edge to edge, bisecting (dividing in half) the upper angle, crease, and then unfold back to this image.
Step 3. Turn your model so that it looks like this.
Step 4. Fold corner to the opposite edge so that the corner lines up with the point where the crease hits the edge of the paper.
Step 5. Fold corner to corner.
Step 6. Fold the front top flap down to cover all the layers. Fold the back top flap backward (there will be only one layer to cover in the back).
Step 7. Open cup by pulling the two sides apart!
Step 8. Done
Back to the Origami Diagram Page at Craig's