A 45 degree angle of perfection!

The backhand component should be a combination of many things, however, more importantly is the following:

(1) Proper weight transfer from back to front.
(2) A high and complete follow through from beginning to end.
(3) Balance and good posture with a straight back and lower leg
bend.

Once you have achieved this, you'll begin to see a difference that will change how you view your enire game and approach.