1. Knuckle push-ups: You should perform push-ups on the various fists you use so your hands get calloused and get used to less pain. These push-ups should be done on a hard surface, preferably a wood or tile floor. If you’re going to punch or hit with a certain fist, then you should be able to do a push-up with it, including fingertip punches. Otherwise, he might seriously hurt himself using that punch in the real world.
2. Constant makiwara training: Using makiwara will toughen your hands and stiffen your knuckles. Makiwara training should occur slowly over time and should always stop at the first sign of injury. You can build your own makiwara at home, or you can find more expensive models through various martial arts supply houses. When choosing a makiwara, be sure not to use a model hanging on the wall. These are not true makiwaras and will not provide any bounce. You hit a solid wall and this is a recipe for a broken hand or wrist.
3. Keep your fist clenched. The quickest way to insult you when you hit something is to have a slack fist. Use your thumb to press against the sides of your fingers to create a fist that feels like someone throwing a rock.
4. Don’t let the punch bounce off the surface of your target. If you’re practicing hitting a hard surface, like a makiwara, make sure your fist doesn’t bounce when you make contact. You must hit the target, hitting all the way, but sticking to the target at the same time. If you deflect your fist away from the target, you can easily open your knuckles.
5. Train periodically by breaking the board: This will also help you force yourself to clench your fist hard, punch all the way through your target, and create a punch much faster. The board does not give. Either you hit it right and it broke, or you didn’t and your hand will hurt.