for power i would say the best way is a little step forward with your lead foot on the jab cross and then take a small step forward and right with your right foot with the left hook, this is the basic principle of power transfering weight from one leg to the other while strikeing your target, try that on a heavy bag and you will notice the difference in power in your left hook, then apply what youve learned from that into all of your punches to perfect your form and balance as your boxing, hope this helps