Compressing the golf ball is when the club head drives through the ball on impact, trapping it between the club face and the ground. The resulting divot will appear ahead of the golf ball. By compressing the golf ball, it will travel more accurately over a greater distance, and it will have a greater amount of backspin due to the impact of the club face's grooves on the ball.
Shift your weight to the rear leg on a shallow backswing. To achieve this, focus on swinging the club around your body in order to set up a shallower approach angle to the ball.
Shift your weight onto the lead leg and ensure the trailing shoulder (the shoulder farthest from the golf ball) moves toward the golf ball.
Swing the club downward, following with outward and forward movements to achieve a forward shaft lean at impact with the ball.
Turn the knuckles of the hand that's on top of the golf club slightly toward the ground during impact to help trap the ball between the club face and the ground.
View the position of the divot created by your shot. If the divot is on the forward side of the ball, then you have successfully trapped the ball during your swing.