Now it's time to cut your pom-pom free from its cardboard template. Use sharp scissors and cut as close to the center line opposite where you just tied the other piece of yarn as you can.
It's best if you can get all the threads in one cut, but that is often difficult when you're working with a large pom. Don't worry if it doesn't look perfect; you can always give it a bit of a haircut later if one side ends up with a really long piece.
Once you've cut the pom-pom open, slide your knot to center if necessary and tie a stronger knot in the yarn that is holding the pom-pom together.