A fast tennis ball is sometimes just what you need on the court -- the greater the speed, the less time and fewer options your opponent has for returning the ball. As a rule of thumb, you'll want direct hits for speed and more glancing hits for a slower ball and greater spin. Speed isn't the answer to every shot -- the more speed you have, the less spin you produce -- and it certainly takes more finesse than just wailing on the tennis ball.
Note where the ball makes contact with your racquet. In general, balls that connect near the throat of the racquet actually have the most built-in power, according to the research branch of Tennis Warehouse. However, the high middle-third of the racquet tends to produce the most speed. As a slow swinger, hitting near the throat makes for faster shots. If you take faster swings, you can live in the high middle-third. Normally, you'll only have time to consider this placement on your serve.
Mind your footwork, especially your split step. Don't wait until you make contact to put your body into your shot -- as the ball comes toward you, make a full-body extension, exploding forward just as it leaves your opponent's stringbed. Split step into the ball by hopping about an inch off the ground, thinking of your legs as loaded springs. For the maximum amount of power, you'll make contact with the ball at the top of your split step.
Keep it loose. Instead of overswinging in an attempt to pound the ball out of the court, practice a fluid swing with a plenty of follow-through. You'll produce far more power from a smooth, controlled swing than a tense stroke, no matter how much punch you put behind it.
Choose a stiffer racquet with a denser string pattern if you want to focus on fast shots. A stiffer racquet gives less on impact, which puts the energy of your swing directly into the ball; conversely, a racquet that bends dilutes the energy of your swing. Likewise, a dense string pattern makes for a quicker rebound. You'll sacrifice a little bit of your topspin potential with a dense string pattern, however.
Lower your string tension to the range of about 3 to 6 pounds. This gives your strings a little more spring, meaning the ball spends less time on your stringbed and more time bouncing off your racquet.
Dan Ketchum has been a professional writer since 2003, with work appearing online and offline in Word Riot, Bazooka Magazine, Anemone Sidecar, Trails and more. Dan's diverse professional background spans from costume design and screenwriting to mixology, manual labor and video game industry publicity.