Couple things. You should have an idea after the first service game of what kind of returns your opponent is hitting. Is he taking it early, chipping it back, coming in after, which side is his weaker return, is he mostly returning cross court, etc.
Next, one thing I see so many people do is when they hit a good first serve, they stand there admiring it hoping it doesn't come back instead of getting ready in case it does. Always assume it will come back.
Are you split stepping right after your return. You should be serving and then essentially split stepping right away in anticipation of your opponents return. Make sure you look at your opponents contact right after you hit you serve and split.
5.5. Teaching Pro. Ranked top 10 middle states mens open.