One thing is when you get a ton of tips it is just too much to take in and you can overthink.
So the one tip that will really help is to hit your trophy pose and make sure that your palm is "waving" at the sidefence while you are tossing. When you swing to contact it will be a karate chop at the ball, and when you finish, the palm will be upside down and against the sidefence again.
Just work on that and dont worry about anything else yet. That has really helped me at least.
Please help TT Member BruceD get a wheelchair so he can play tennis again - http://tt.tennis-warehouse.com/showthread.php?t=496820