Set the trail wrist back: bullseye down, bullseye away
Craig Hanson gives a trail-hand (right wrist) checkpoint for the backswing: pull the right hand back so the wrist breaks back on itself, showing the creases, at about a 45-50 degree angle in the back of the wrist. He calls the position 'bullseye down, bullseye away' and says it keeps the shoulders down so you can release the club more under. He says a fanned-open face instead leaves you with an open face you have to roll over and pull everything back to square, which is hard to repeat.
Channel: CraigHansonGolf
Watch official source at 2:30