There are several competing theories regarding the proper angle of tilt in a golf swing, as well as disagreements over weight shift. Nevertheless, a central tenet that has no critics is the idea that you should maintain a consistent spine angle throughout the course of your swing. This exact angle may vary from golfer to golfer, but it should not vary from backswing to downswing to follow-through.
Examine your alignment at setup. Traditional swings, both one-plane and two-plane, feature a spine tilted slightly away from the target. The new "stack and tilt" swing will have a vertical spine angle at address (on the side-to-side axis). There is not necessarily a correct angle; just be aware of what angle you align yourself at.
Maintain the same angle during your takeaway and backswing. Most swings will involve a weight shift from front foot to back foot during the backswing as the back knee bends. The stack and tilt swing has no weight shift, and the back knee actually flexes to a straight position. Again, these differences are not significant as long as the spine angle remains steady.
Resist the urge to straighten up at the top of your backswing. Amateur golfers have a tendency to lift their shoulders, straightening at the hips at the top of the backswing. This move requires that they have to lunge forward on the downswing to the exact perfect position to avoid hitting it fat or thin. Some golfers, generally better golfers, have the opposite problem, bending down to the ball at the top of the backswing. This move leads to the hands getting caught behind the right hip in the downswing, and blocks the swing to the right.
Rotate around the spine on the downswing. Begin the downswing with the lower body and hips, turning open to the target. Allow the rest of your upper body, shoulders and arms, to whip through the zone, rotating evenly around the axis of your spine, which should still be at the same angle as it was at the address.