In regards to the last post where I mentioned any punch should be generated from the hips, today, the technique in focus is the impact of the punch. Many of us who use boxing in training sometimes take this for granted thinking because we wear padded gloves, we would not have any problems with how our fists hit the mitts or the bag. However, it is critically important that the impact should always be on the the first two knuckles. This is to keep our wrists as solid as possible during impact. Should we shift it to our last two knuckles, we put our wrists in a vulnerable position where we can bend our wrists easily. Couple that with the power going through our arms, we can easily sprain or break our wrists if done incorrectly.
Start by focusing on this as you warm up. It requires abit of getting used-to but once you get the hang of it, you are saving yourself from wrist injuries if you really enjoy your boxing!