This is what I was talking about in the other thread:
I watched the first of a series of serve videos today. It was sent to me from FYB for free, and what Will has done is to get Pat Rafter to demonstrate how he serves and what is in his head and how the serve feels to him. If he wants to carve a slice, he visualizes an exaggerated carving, though the dwell time does not really allow that. If the toss is not perfect, he makes micro adjustments to his motion to compensate. He basically uses the second serve for both serves. He strives to make the returner hit "outside the stencil," meaning not on the sweetzone, by making the ball spin and move in such a away that it is always eluding the racket.
Will intervenes from time to time to make a point.