For Simplicity’s sake, let’s assume that your backswing has been completed correctly: back turned to target, weight shifted to trail (back) foot, on plane --- so that no major compensating moves need to be made to return the club to the ball.
From the top of all good golf swings, the very first thing that happens is a slight lateral move of the hips toward the target, which shifts the weight from the trail (back) foot to the lead (forward) foot. As your lower body, with the hips leading laterally, moves toward your target, your arms drop into hitting area (hip level), with your right elbow working toward your right hip. As your arms drop, but not before they do, your hips, then shoulders will begin opening up to the target. This will allow you to maintain the angle between your left arm and the club shaft, setting up the latest possible release for maximum club head speed at impact and enabling you to come at the ball from inside the target.
Some words of caution. First, the lateral move of the hips is slight and barely perceptible. If your lateral move is exaggerated to the point where your head moves past the ball, or your weight gets outside your left (lead, front) foot, you’ve over made the move. Second, all of the previously cited moves must be made in one continuing fluent action. When executed correctly, this unified move will drop the club into the proper slot and permit you to swing naturally, freely, correctly through the golf ball. Although this explanation of what starts the downswing may sound complicated, it really isn’t: just make the little lateral move with your hips first, and everything else falls into place.
Ron Beck is the Head Professional at Fox Hopyard Golf Club, East Haddam, CT.
He can be reached at (860) 434-6644 or firstname.lastname@example.org