- Cut a half circle.
- Place your finger over that half circle.
- Lift up your knife, go back to the beginning of your cut and cut the rest of the circle out.
- Practice! Practice! Practice!
Download the instruction sheet on how to cut circles: Cutting Circles
Or, you can cheat and buy a teeny tiny hole punch, but sometimes you can't get into the middle of a larger cut with that, so you might as well man up and learn how to do it someday!