Players who have a good slice can be very frustrating, but there are several things you can do to handle this shot better.
First, try to keep your position on or inside the baseline. A slice will stay low and you must be ready to move right towards where the ball will bounce. Next, stand in a very low ready position (bend your knees) and expect the ball to be below knee level at the point of contact. Don't be surprised by the ball skidding and not coming up. Hit the shot with your normal smooth swing and speed.
Finally, try to come in to the net. Players who slice will miss more in the net or pop the ball up more if they know you are in a volleying position. You also won't have to deal with the low bounce if you hit it out of the air.
As with any difficult situation, don't panic or get frustrated-stay cool, calm, and collected!