Creating a connection between the turn of your shoulders and swing of your arms promotes a more efficient golf swing with less moving parts. Most amateurs' swings have too many moving parts and as a result develop a great deal of inconsistency. To improve the connection in your swing I recommend The Ball Drill. Find a ball about the size of a slightly deflated volleyball and pinch the ball between both biceps while also having it contact your chest. Once the ball is in place, grip the club and begin to make short swings. Gradually work your way up to a full-length swing while swinging slowly. The key to performing the ball drill is that the ball must maintain contact with all three points while you are swinging. The length of your back swing may feel shorter and more restricted. Connecting the motion of the body and arms will eliminate unnecessary moving parts in your golf swing and make it easier to repeat.