What are some good example shots where english (sidespin) is required?
Here are a good collection of example english shots from the BU Summer School Boot Camp. These are excellent shots to practice as a drill. Demonstrations of most of these shots are in the following videos:
The aiming systems used in the 2nd video are covered in great detail in the System for Aiming With Sidespin (SAWS).
Many game-situation sidespin examples, strategies, and techniques are demonstrated in detail in the following instructional videos: