by Rob ITST » Thu, 11 Feb 2010 22:20
Some people watch the ball for the timing, but I use what it says in the TopSpin school: "Release the button just before he swings". I watch the racquet, and do just that.
First, you need to make sure you have the correct timing for the button release. You can do that in the School, but I prefer this: Hold LT+RT, and serve without aiming. If it goes in, you're timing is right. If it doesn't then it's wrong.
Focus on that first, then start trying to aim closer to the lines.