If you can straighten your arm without touching it, you’re too far away; you’ll have to lunge forward to hit your target, which will take away from the force of your punch. Move a little closer. If your elbow is bent at a right angle, or close to it, you need to step back a bit. The term “one-inch” is actually an estimate here. The point is to punch from a very close distance, not from exactly one inch. After practicing the punch a few times, you should be able to figure out the right distance from your target without having to extend your arm beforehand.
Don’t point your toe to the left or right of your target; it should be pointed straight ahead. Don’t lean forward toward the target, as this will prevent you from being able to punch as hard.
Be sure your torso is centered, rather than leaning forward or backward.
If you’re trying to take someone by surprise, you want to make a fist right at the last second. You can fake someone out by holding your non-punching hand in a fist and cocking it backward; they’ll be watching that hand instead of the one that’s about to go for the punch.
Make sure your wrist doesn’t weave from right to left as you punch. You want to flick it up and straight toward your target.
