This shot can be used to clear the net at height then curve left in the air and at the bounce. The serve technique also means that it can be hit quite hard.
How: The racket face needs to be going from the lefthand side to the right and from below the ball to the back of the shot. This creates the topspin.
Points to remember: The left arm should be high, pointing up to the ball which means that the whole body can reach up on contact.