Every player has a weak zone. I define the word zone as an area of inefficiency when hitting a shot. For some player it is low-shins to thigh, and others it is medium, thigh to mid waist and others still, high waist to chest.
Once you sense a zone to exploit you need to keep the ball there as much as possible. Low-drive serves, medium-junk lobs and short z serves, and high, ceiling balls and high half lobs; these are examples of serves to expose the weak areas. During the rallies working the ball around the court with a variety of shots such as low wide angle passes, medium junk style passes, or cross court ceiling balls are three ways of attacking aforementioned zones of weakness. It is an art form and I love watching the clever player who cuts off a lob and does not hit a low pass but a soft overhead that will not come off the back wall.
This forces the server to make a decision between getting greedy and shooting that ball or being conservative and going to the ceiling. Thus, the medium zone is being exploited by said receiver of serve. Look for the zone in that pesky opponent that is your nemisis. Dial up that zone and drive your opponent up the wall literally and figuratively!