The one plane swing requires that you bend from the hips more than the two plane swing set up. This move is counter balanced by your buttocks going back more, thus maintaining your balance on the balls of your feet.
This is a great shot to practice because it is a mini version of the full swing. Make sure to finish near your front pocket and practice distance control by taking your backswing up to your pocket, chest or shoulder height.
Since your body is bent over more in the one plane swing the shoulder plane resulting from the body pivot should be pointing to the ground just outside the golf ball.