Start "Low and Slow" ...elbow positions below the shoulder level ....now go to the trophy position by bending at elbow. Tip of racket will go behind the head (not above) ...the rhythmn in the service is slow - slow - fast
...the elbow bend has a "brushing the hair on the back of your head" feeling to the movement altho the hand is not directly behind the head but rather more over the right shoulder