Ah, well if you know anything about boxing it's usually about combos and working types of punches into movements. Work up the bag toward the "head", work down the bag to the "belly" using different punches. A good list is combos of 1-Jab, 2-Straight Right, 3-Left Hook, 4-Right Hook, 5-Left Uppercut, 6-Right Uppercut. Try 1-1, 1-1-1, 1-2, 1-2-3, 2-3-2, 3-2-3, etc. Try intervals of 3 minutes punching and one minute rest, change it up and work the dodges and blocks.