Be careful in how you do this. Trying to manipulate the arms to achieve a result and not really getting at the origional problem will be a backward advancement. It may work for a little while, but very soon will go away and create some sort of other issue.

Make sure all you are doing on the first 18 inches of the takeaway is turning your shoulders back, and letting the arms and hands take a ride. This is enough to put you in the correct position to attack the ball at all the right angles.