It is interesting. I see some answers that give a way of returning side top. But I don't see the principle, the idea behind how you approach the ball.
For this you need to know which sidespin; which way the ball is curving; and which side of the ball is the inside of the spin (where the spin will have the least effect on you).
So, for a ball that is curbing towards your FH, (reverse pendulum, or hook or BH) for the easiest time with your shot you want to contact the ball on the inside of the spin which is the BH side of the ball.
With a ball curving towards your BH side (regular pendulum spin), you will also want to contact the inside of the spin for the easiest way of handling the ball.
If you are good and you really know what you are doing you could contact the outside of the ball (where the spin will have the biggest effect) and use the spin to your advantage.
Recently, getting to train with Mark Croitoroo who is learning to play lefty as a result of an injury to his right shoulder, I have been able to see some totally crazy returns. He does some stuff that looks like penhold punch block returns that are utterly nasty. It doesn't matter if the ball is top or backspin, he will adjust the blade angle according to the spin and do these evil returns. He will go will contact the inside of the ball and slide his racket against the spin and forward and, with very little effort, he will launch a rocket taking the sidespin and giving back the nastiest junk ball imaginable. Or he will drop the heaviest top/side balls short by sliding down and in against the sidespin. Or he will hook the ball forward contacting the outside of the ball and get crazy sidespin because he is taking the sidespin of the serve and adding to it.
But that is much harder and takes much more technique. However, the other returns require you read the spin accurately.
For instance, to drop the top side ball short, you need to be on the inside of the spin and you need to slide down and in. Or you could slide straight in. Can't describe the motions. And I can do it in practice when I know what is coming. But in game situations, I will mess that up.
For heavy back/side, you have to be almost straight under the ball and slide inward if you want to drop it short. But there are other ways to push it long. And if you are inside the spin, topspinning these is possible too.
But those nasty punch shots that give those ugly junk balls seem cool as heck to me.
Anyway, the key to returning any serve is reading the spin correctly. And if you do this, there are always many ways to return any serve.
Sent from The Subterranean Workshop by Telepathy