Squash is a game played in close quarters. You are constantly jockeying for position with your opponent. It is important to remember that you have the right to play the ball where you want. There are two reasons that this is beneficial. The first that you get properly set for your shot and the second that we can force our opponent out of position.
Getting properly set to hit your shot is crucial. It allows you to get balanced, make a proper shot selection and not rush your swing. All 3 are crucial in squash. If your opponent hits a ball down the centre and you are not ready to hit then your shot selection if you attempt to hit is definitely going to be limited. Your execution is also likely to suffer. If you are not set to hit you are better to follow it back, get set, choose your shot and hit it. If your opponent is behind you he has to clear out of your way as it is your choice as to where you want to play the ball.
The second advantage of this is directly related to the last point. If you have a ball that is coming through the centre, and you take your space and follow it back your opponent will have to move out of your way to give you the space you need to hit your shot. If you know where he has cleared to you also know where you have an open space to hit. Think about a situation where your opponent over hits a drive and it comes off the back wall. If you hit it immediately you are still in the back of the court. If you follow it out as far as you can to the middle of the court you are in a better position to hit from. You have also forced your opponent out of the middle of the court as they have to let you play the ball where you have chosen. A definite advantage!
Squash is a game of patience and is also a very tactical game. Learn to take your space and play the ball where it gives you the most advantage.