An attribute of almost every great hitter is a fast swing. A fast swing is indicated by several different measures including the speed of the bat as it travels through the entire swing process, and the speed of the ball as it exits the bat after contact. Those two measurements enumerate 2 of the primary objectives of a great hitter: swing fast through the ball, and hit the ball hard. Research proves that, in general, a higher bat speed and a greater exit speed after contact result in the longest home runs and the most powerful hits.
Therefore, each quality must be addressed, in tandem, during drills. It is not enough to practice swinging a bat fast, by itself. It is not enough to practice making contact with the target, by itself. The two objectives must be coupled in order for maximum achievement. Aim to make every swing fast, and in particular focus on increasing the speed of your swing after contact with the target. Accelerate to completion.
And, swing at a target. Dry swings (without a target) are more of a conditioning tool and may have a purpose for some batters; but swinging a bat in and of itself will not make a hitter great. A hitter must swing at a target, either a stationary one on a tee or a moving target as thrown, tossed or pitched. Greek historian and author Xenophon said, “Fast is fine, but accuracy is everything.” Combine the 2, and become great.