The key to this project, I think, is making the strips the right width and length - I've definitely messed up a few. There is also a tension that must be maintained as the strips are folded over and then under. The one on the left took longer because I left the strips really long and added extra folding steps. I started to trim them, but I liked the look of the pattern made on the underside, so I left them. That one's also been used, ewwgrosssorry.