Most people I see in training, including many of the decent fighters are not accurate with their punches. Not because they can't be, but because they are not in the habit of training for accuracy. People usually focus on the speed and power of the punch, and less on the precision. Obviously, those elements are crucial for an effective strike, but never forget the WHERE to hit.
The difference between landing a punch on the chin, or on the cheek bone is like night and day. One will knock someone out and the other will do little to no damage when adrenaline is pumping. My two tips for getting into the habit of punching accurately are:
1- No matter what you're doing or what you are hitting, it can be a heavy bag, pads, or your partners face, always imagine that you are hitting a chin, jaw, or the temples.
2- When you punch, even if you're wearing wraps and gloves, focus on the fact you're hitting the target only with the two big knuckles in your fist.
Get in the habit of focusing on these two things when you train your strikes and I guarantee your punches will become lethal in their accuracy.
ICCS head instructor