• Use the hand you write with.
• Make a fist with your thumb outside, not tucked inside. If it’s tucked inside your fist, when you punch someone, you might break your thumb. The thumb goes across your fingers, not on the side.
• Don’t be like in the movies—don’t aim for the face. Face punches don’t usually stop people, and you can miss when they duck their head or break your hand on their jaw. If you want to get away quickly, or end a fight, aim for the chest, or the ribs. If you really want to do some damage, e.g., you’re being attacked, aim for the throat, which will make it hard for your attacker to breathe for a hot minute.
• When you punch, you want to aim and hit with your first two knuckles. Not the flats of your fingers, and not your ring or pinky knuckles, which can break more easily. You can use your weight, if you’re on your feet, to add wallop, and spring into a punch with your feet and torso.
Useful information, esp. if you haven’t taken self defense.