Watching the ball is a huge part of hitting it solid on the tennis court. Another part of this concept is getting your position to be consistent based on what you are seeing with your eyes.
If you are a competitive tennis player, you want to win. The problem is, so does your opponent. In fact, everyone wants to win.
Since the game of tennis has gotten faster and faster, it often feels like you are hitting from an off balanced position. Whenever there is time, try to synchronize your last step with the ball contacting your strings. This means getting your foot to hit the ground as close as possible to the ball hitting your racquet.