Golf Swing - Setup - The Hips
Not Tilted

Tilted Too Much

Correct

Closed at Address

Open at Address

Parallel at Address

If your chin is in the correct position, and your spine is long, and your knees are flexed the correct amount, the golf club will not sole correctly on the ground until you tilt or bend over from the hips. You do not want to bend at the waist. You always want to bend from the hips. The difference is if you bend at the waist your spine will bend (not good). If you bend at the hips you can maintain the spine angle and sole the club on the ground correctly (#22). If you do not bend at the hips, you will not be able to sole the golf club (#20).
When you bend over from the hips you have to make sure you do not straighten out or lock your knees. When you bend at the hips you have to pay close attention to making sure you do not bend at the bottom of the spine.
At address the hips are parallel to the ball flight line. As the golf club swings back down from the top, the first move from the top is for the left hip to move an inch or two parallel to the target line and then the left hip should begin to turn backwards out of the way so the golf club can swing back to the inside after impact.