Some have mentioned big angles and first step back. You must also learn and know the flight paths of certain balls hit. Righty hits one in the air and it will tail toward to your glove side if you're righty or hand side if you're lefty. Righty hits liner and the spin may have it moving opposite. Same with lefty. Your 1st step back should be determined by what side hitter you have, and how he's hit the ball, fly, liner, hopper. If a righty hits a fly ball to CF, you will want to take your 1st step back to your left and then read the flight from there. All routes can be practiced, have the coach fungo the different types of hits and practice seeing the flight path of the ball. Also, always try to put yourself in a position to throw as you receive the ball. Hard to do when running one down overhead, but most times you can get behind the ball and be ready to throw. Good luck.