Hahaha...let me guess what you need the circle cutter for! I actually just bought myself one a couple days ago, and I have the same exact problem as you. The fabric keeps shifting, and I don't get perfectly clean circles (although they are fine for the fabric flowers). I got annoyed doing one layer at a time, so I started doing 5-8 layers (depending on the fabric). It's hard to do a smooth motion like the video, and I put too much pressure. I got little blisters on the bottom of my hand! I told you, I'm not good at this!!
BTW, I'm not addicted to fabric, and went to Joann's again. Fabric was on sale, and buttons are 50% off (for the centers). "Saved" our bank account so much money...Yay!!
Hope you have a good New Year, and thanks!!