A lot of players think as they get older that they can’t turn and some are right–however most find with this simple test that they can turn farther than they thought.
Standing straight up lay a club across the chest at the shoulders and turn the right shoulder (backswing turn for a right handed player) as far behind the head as possible. See what angle to shaft is at–most times it’s 90′ or more. Then turn the other way–left shoulder away.
A great way to work on the turn is to get into golf posture and cross the arms across the chest, then make a backswing turn, feel the lower body start to engage, the upper body winding up and the weight getting into the trail heel. From there shift the lower body weight back to the lead leg, then straighten the lead leg and turn the lead hip out of the way. If done correctly the hips will be open about 20-30′, the lead leg fairly straight, weight about 90% into the lead leg, chest facing the ball.
The attached drill starting about the 11:00 minute mark is great helping with turn, weight shift and posting the lead leg.