Originally Posted by Randy H
Take the ball early, and use the angles of the court.
Just to elaborate a little more on this - The key is to find ways to take time away from your opponent, and to find the openings in the court. You don't need pure power to do this, you just have to be a little creative and willing to try different things.
Most pushers love a big hitter who will try and blast winners corner to corner until they self destruct with errors. How can you break the court open? Use the angles of the court to your advantage. Hit a couple of hard deep shots to get them behind the baseline, and then throw in some angles (especially to the backhand side where it's harder to throw up a moonball stretched out of position).
Another option is to test their ability mid court. A lot of people don't know what to do with a ball that lands around the service line. Either you hit the winner outright, or you either risk being passed, lobbed, or come up with a volley. Dare him to be the one to come up with some aggressive shots in "no man's land".
Don't focus on power, focus on court position and placement
You don't have to crush a volley, drop it short and force them to have to hit up on the ball which will give you more sitters for the volleys while they are out of their comfort zone.