Vijay Singh is a great swing to model because he has great freedom through his swing, allowing him to get a great hip and shoulder turn and unload on his downswing through to an extended finish position
Practice your entire swing in super slow motion, this will allow your mind to focus on the correct muscle movements needed instead of trying to make your brain work on the correct movement while you are swinging, just do it don't think it
This drill is great for people stuck in an office or in bad weather, hook the right hand under the left and practice your backswing and downswing with a perfect right and left wrist position