Many people run towards the sideline for a ball, hit it back, and stay there looking. Your opponent has thereafter a lot of space to make you run.
There is a better way to strike and cover the court efficiently, so you don’t leave too much of an open court for your opponent.
You do so by hitting open stance and pulling across, not only with your hand (or hands for the two-handed backhand), but also by loading on the outside foot and pushing off on this foot towards the center, as the inside foot lifts or slides towards the center (and perhaps somewhat backwards) as you turn while you hit.
You may need to get closer to the ball initially to be comfortable with this technique. You may need to emphasize your finish as well.
This will increase your power and spin, aiding in the acceleration of your windshield-wiper stroke, and help your control of your balance too.
You shouldn’t run too hard towards the center, otherwise you open the side of the court from where you just stroked for a wrong-footing shot.
Be always ready to pivot and run straight. Side-stepping is good to wait around, but not to reach a distant ball.
Watch the new DVD, the Best of Oscar Modern Tennis Methodology to see how can this be emphasized for every stroke.