true punching power comes from being gifted. some people got it and some people dont. its not even really a sense of transferring weight or being strong or anything...its more of a mystery than damn near anything in sports. you can increase it slightly by doing certain things, a lot of which are superficial and more based on intimidation than actual power, such as being more physically imposing, or even looking more aggressive when you throw punches, but i wouldn't really concern yourself with power as much as getting punches off in a timely and efficient fashion, as accuracy seems to be the most "fixable" aspect of power.