Tennis: Serve - Racket Lower than Tossing Arm

....from the trophy position, keep the legs bent (or bend slightly more) and simply lean rearward whilst dropping the racket into the power position (with a straight back) ....THEN extend legs followed immediately by elbow extension ..in the past I was extending my legs during the racket drop ...this was incorrect

Lead with the tossing arm. Strings of racket face your knees in a delayed following action

keep racket lower than tossing arm at start ...do not bring up both arms together ....reason: you do not want to stop in the "trophy position" ....you want to be always moving thru all stages of the serve to gain max momentum, speed and power

Note how player stays inclined thru shot ...she does not straighten her spine immediately post impact ...instead she goes "shoulder over shoulder" into the follow thru ...left shoulder stays lower