Different mental, physiologically and physical factors contribute towards improved punching.
Practicing boxing and other martial arts helps the player in maintaining a good balance. Nobody can deliver powerful strikes without a balance. If you hit your opponent without balance, his chances of win will improve.
A solid and strong stance is directly related to balance. If your stance is weak, the punches and strikes will also be weak. Delivering strikes with strong base gives power to the player.
Waist/ Hip Rotation
A player must know how to turn his hips and waist in co-ordination with the strike. This will help in developing more powerful punches.
Speed and Mass.
Faster the punch, the more powerful it is. But, don't consider only one side of the coin. If the speed is the only key to powerful punches, then lightweight boxers would have got the credit to have hardest and powerful punches. But, they lack in the mass factor. Heavyweight boxer might not have high speed, but mass is high and the combination of both produce more powerful punch.
Relax Before Strike
Observe some best punchers in boxing and martial art, you will see that they relax their muscles before striking.
Practice to Strike Heavy Bags, Focus Pads and Punch Bags
Boxers with powerful punches practice by actually hitting something, which exclude shadow boxers. The practice is done on big bag, speed balls and body shields. Punching in air is not enough, as you need to put on some force for a hard hit.
Focus on Speed and Power Mentally
No magic is related to powerful strikes. Combine mental focus with scientific training principles to become fast and more powerful.
Fist Alignment with Punch Bags
A proper fist alignment is the one where the fist ends up in a 45° angle at the end of the punch. The punch at forty five degree is fast, strong and natural, but each person is different and his method of punching also varies. Find out your specialty yourself.
Play the Mind Game
Mind is your most powerful weapon. Always think that you can defeat your enemy with superior skills, and you will win it.