Don't make Unforced Errors. No, really. But that's pretty hard to do, so, instead, an Amone explaination!
There are a few solutions:
The easiest is: Push! It's really easy, I promise you. There are plenty of ways to do it. When I push, for instance, I hack, because my slice is accurate and consistent. Other people dropshot everything. Some hit relaxed topspin right at them. All that stuff you do when you are trying to be really consistent, just make it twice that, and lazier.
Another is to move him around. Drop him, lob him, smack it to the corners. Make him run every point. Their style of play is built around getting to every ball, good. Make him work for it.
If it's your cup of tea, rush the net. Nothing is more fun than getting an infinite number of opportunities to hit great volley winners, and when they're not pressuring you at the net, like pushers don't, that's what you have.