Focus on getting the ball in consistently, use easy serves to take the net with a lob or chiquita, and adapt strategies for difficult serves off the glass based on your skill level, potentially using a lob or block.
Sandy explains the most crucial part of returning serve is just getting the ball back in play first. He talks about how to handle easy serves, which is a great chance to take the net. He also gives you strategies for tougher serves, especially when the ball hits the glass, depending on your current level. This is essential knowledge if you play the left side.