receiving-and-reading-side-top-and-side-under-serves

Hey Rowel, yes these can be tricky if you don’t see the spin well. A really good way is to try to really focus on the contact of the serve, don’t worry about the movement or the action, just focus on when the ball hits the rubber and that key part, this will help you read the spin better. Also try to not rush in too fast to return, try to wait a bit longer to give yourself the maximum time to read the spin and make a decision. Of course if it’s sidespin with topspin you want to avoid pushing these as the ball will fly off or go high, so trying to flick these with your backhand or forehand if you are confident is the best way. 
The last thing I would say is to try to be decisive when you play your returns, it’s when you are stuck in two minds that the mistakes usually happen, it’s better to go for a push and stick to it or go for a flick and stick to it and make mistakes this way than changing your mind, this way you will start to read what happens each time better.
 
I hope this makes sense and helps you!