A great video showing some of the common threads of the one handed backhand in the preparation phase.

Things to note:

1 - Do not take the racket back with the hand..make the take back with the shoulder turn

2- Note the angle of the racket to the hand- they vary slightly, but it must be that your racket head must be above your hand.

3 - Arm bent on the take back

4 - Elbow of the non racket arm high.

5 - Left foot makes final adjustment step and its an outwards step

6 - Weight transfer in a heel to toe forward movement.

Second video to follow.

Video from TennisOxygen