This is where PRACTICE comes in.
1. Your body is moving forwards as you swing up and out at the ball. The amount depends on who you are and what your intentions are.
2. You shoulder's pivot from one and only one spot.
3. If you're going to stay back, your body doesn't move into the court as much as....
4. If you're moving to service line position, you toss has to compensate for your body moving more forwards.
Basically, the goal is an up and outwards swing with forward angle, and just as important, the highest net clearance you can get with the fastest swing you can muster and the deepest part of the court to get the highest bounce and biggest twist effect.
Depending on how fast you can swing, the height over the net can vary, especially since we all swing different speeds.
I like to try to aim 3' higher than the net. My slow 60 mph twists usually bounce from upper chest to mid shoulder heights.
My safe second serve top/slice might wander in a hair faster, but only bounce maybe tummy to mid chest in height.