If you already rolled a joint and its a little loose.... You can tighten it up by using a dollar bill. Just fold the bill, place loose joint in fold, roll back and forth a few times, remove tight joint. Breathing heavy on the joint like you are trying to fog a mirror, will help it tighten up in the bill. Also helps during rolling process to keep things soft so you don't get loose joints. Note: After tightening in a bill, the joint will tend to run a little. Keep an eye on it.