If you don’t feel comfortable holding the ball while you cut it, secure the ball in a vise grip.
Make sure the blade isn’t pointed toward your fingers or you could accidentally cut yourself if the knife slips. You may also use a craft knife, but it may not be as strong as a utility knife.
Don’t make your slit any longer or else it could easily fall off of furniture legs.
Once the ball doesn’t have an odor, it’s ready to use.
If a pen doesn’t work on your tennis ball, use a marker. The marker line will be noticeable when you finish your cut.
Imagine your hand is a claw so you’re only grabbing the ball with the ends of your fingers.
Stay attentive while you make your cut so you don’t accidentally hurt yourself.
Turning the ball makes it easier to cut and helps ensure you’re halves are the same size.