Many times in a match I will see a player making an error on a shot when their opponent is in a poor position. For example, your opponent might be in "No-Man's Land," (anywhere between the baseline and the service line). You panic and hit the ball long, wide or in the net. Instead, when you find your opponent in a bad position, many times the best reply is to hit the ball "to them." This will force them to try to win the point from a poor location. Thus, the burden to hit a great shot will be placed on them. This will allow your opponent to make more errors than you.
Many players, especially in doubles, make too many errors because they always try to hit the ball away from their opponents. You will win more points and commit fewer errors in many cases by hitting the ball to your opponent when you find them in a poor position.
Good luck on the courts!