Thrusting the hips towards the ball is a HUGE fault in many downswings. You loose your spine angle, which it turn destroys your swing plain and will make you loose balance at the finish. Check out any mags that have a rear shot of a pro's swing. Its amazing how the spine does not move foward or back.

I struggle with maintain spine angle and hip position. You must rotate the hips, not thrust them. It might be the single hardest thing to learn. Its much more natural for most people to start rotation with the shoulders.

I have always loved the "sit on a barstool." Also, remember to keep that head up when setting those hips, dont bury your chin.

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What's in my bag....
Cleveland VP 2 Blade Putter
Ping Tour Wedges, 54 & 60
TaylorMade rac LT2, 4i thru PW
Tour Edge Exotics Iron-Wood 21* 3i - Aldila NV 90 Stiff Shaft
Ping G5 18* 5 Wood - ProLaunch Blue 75 Stiff Shaft
Ping G5 15* 3 Wood - Aldila NV 75 Stiff Shaft
Cleveland HiBore XL 9.5* - Fujikura Fit-On Red Stiff Shaft