I don't consider myself a big puncher but i do use speed to generate my power, and also timing with my counter shots. Also IMO 3 of the most important things when throwing hard punches are Hips, Shoulders, Feet. When im jabbing which is my best weapon i always throw it like a whip and that generates the most power for me when i jab, but like i said im not a hard puncher but i am quick puncher and thats how i generate the power anyways.