Get synchronized with your upper and lower body moving as a unit. Smoothly decelerate the club once the ball is on its way. Your finish should only be slightly longer than your backswing. Hold your finish position until the ball lands on the green. It’s a good way to instill balance in your overall motion.
Letting one part of your body race ahead of the others. (Most weekend players tend to power this shot with just their hands and wrists.) Try to swing through the ball as opposed to hitting it with your lower body constantly rotating toward the target.
Think about it: If your putter is moving on an arc (typically swinging back slightly to the inside and open then returning to square for the strike before arcing back to the inside on your follow-through and closed) the face is moving directly at the target for a mere instant. If this instant doesn’t happen at impact the ball will start left or right of target and miss the cup.