Take your guard stance close to the bag with your hands wrapped and gloves on.

Dip slightly by bending your rear knee and drop your rear hand a little, palm facing you.

Drive up through your rear leg, rotating your hips and shoulders toward the bag.

Bring your rear fist up in a tight arc under the bag, keeping your elbow close to your body, and hit it with your first two knuckles.

Return to your guard immediately and repeat, keeping your lead hand up the whole time.