TIPS:

Bat Angle
Correcting a Weak Swing
Finishing the Swing
Flat-Snap Hitting
Front Toe Closed
Hitting Off Front Leg
Level Swing
Looping
Lunging and Over Striding
On-Deck Preparation
One Swing
Perfecting the Stride
Plate Coverage
Poor Timing
Proper Hitting Goals
Seeing the Ball
Stance vs Swing
Staying Closed
Stepping Out on Pitch
The Two-Strike Swing

Most of these tips come from the book Illustrated Hitting Guide with permission from the author.

Correcting a Weak Swing

 A swing that is slow in relation to a player’s physical ability reflects a problem in thinking. Often a player slows down his swing in an effort to "just make contact." Making contact is not hitting. This is very poor advice to give a player in most situations. If a player takes a good swing, he will generally make better contact than if he just tries to get the bat on the ball.

Mental focusing on bat speed often corrects a weak swing. One good way of creating this focus is to define the position of the hands in the launch position (right before the swing starts) as point A. Also, define the hands above the lead shoulder after the follow-through is complete as point B. Then have the player concentrate on getting from point A to point B as quickly as possible (without losing his balance or pulling his head). Make sure the hands extend fully forward in getting to point B. Emphasizing "A to B" during batting practice will help to develop a faster swing.