Reread Tiger Wood's book about driver swing

1) Shift weight
2) turn hip. His hip is almost fully turned when his hands are at chest's height during down swing, at which point, his shoulder is still square with the target line.
3) arms movement along with hip and shoulder turn. He makes sure his arms are EXACTLY in front of chest during down swing. Because he has a faster hip and shoulder turn, he has to guarantee his arms can align with hip/shoulder move.