Wanted to go into a little more detail about this video:

Look at the distance this guy can stay at. When he wants to hit me moves just close enough, and doesn't fall in when he hits with either hand. Then he can step around or back a few inches and be safe yet still threatening.

Watch his foot placement whenever you can see it. No matter where he steps, look where his feet and thus his hands and eyes are pointing.

Balance. He can throw multiple very hard punches in a row, punch while pivoting etc without ever looking even a little unsteady. He's got perfect control of his weight, keeps it between his feet and is ready to punch or move at all times.

Posture. Look how straight his back is, how relaxed his shoulders are, that's effortless power punching because his legs are right.

His punching technique is great. Excellent rotation, drive and stability in the right places, sitting down with a strong base, not losing his feet, it's all fantastic.

He's pivoting his feet! OMGWTF take notes