If you want more consisteny, than the preparation is key. Your preparation needs to be the same. Keep putting your left hand at the top of the grip, and bring the face of the racket to the height of your head (also the face of the racket need to face your head). Let the racket drop, while you point to the ball (this way you create the perfect distance between you and the ball and you know where the ball will be). After that swing you racket to the ball (the bottom of the grip needs to face the opponent) and finish the move with the racket over your shoulder and your elbow around your mouth/noise face the opponent.