I think I'm getting somewhere, although painfully slowly. I can now bounce the ball wiht my fingers, not my palm. On preparation, I need to not lean forward but keep my butt over my front foot, and just bend slightly in the waist. As arms come down, I straighten and stand tall. The toss arm goes up parallel to the baseline, and I lean slightly back (instead of leaning sideways as I used to do). The tossing arm is clearly in my sight, and I can controllably move it down and tuck it close to my body. The resulting serve has topspin, always clears the net and lands safely inside the service box.
