Get a heavy bag, watch YouTube videos (good ones are boxing fit factory, title boxing instructional, expert boxing) lots of good mma ones too. The best fighters learn and perfect the basics, fundaments and practice technique over speed or power. Once you have the technique, the speed and power come naturally. Speed and power without technique can be used against you. 1st technique, 2nd speed, 3rd power. Words of my TKD instructor (7th degree black belt)