Fold over the top of the bag once or twice so the kernels cannot escape when popping. Take a hole punch and punch two holes about three to five inches apart where you have folded the top of the bag over.
(Note: You have punched the holes so you can use ribbon to secure the bag shut in the next step. If you want to, supposedly you can staple the bag shut. Keeping the staples two to three inches apart should keep your microwave from sparking. Give it a try at your own risk; I was always too nervous.)
