As a hitter, effectively making contact with the ball is a critical skill to master. Many in the sporting world consider it among the most difficult techniques to fully develop. If it's so hard, why does every great hitter say you must never think when hitting a baseball?
It's because great hitters are made with practice. Hitting takes a great deal of hard work and proper mechanics. If you weren't born with it you can develop it; if you train smart.
I believe hitting is the most over-taught skill in sports. It's quite obvious that a hitter needs a clear head when batting. So why the heck would a coach yell 10 commands at a hitter when he's hitting? I have no idea why they do this. All this does is cause confusion and poor contact.
The key is to keep it simple. Practice hard. The best results come from training your body on one aspect of the hitting process at a time. Over time the muscles in the body will remember how to perform the movement without your conscious thought - that's when you're ready to move to the next step.
The body core and legs are critical for proper hitting form. Emphasize the use of the lower body. All great hitters hit from the trunk out, so get those hips exploding through the zone and that back heel to the sky. Avoid "squashing the bug". This is terrible advice and robs the hitter of virtually all of his power.
Be sure to stay relaxed when hitting a baseball. Your body must be able to react very quickly. If your muscles are tense your body will not be reacting at peak speed and quickness. Make sure you have a light grip on the bat when batting. Keeping a relaxed hold on the bat will help relax the body which will improve reaction time and hitting power.
Last, but certainly not least, work on your baseball-specific vision. Practice following small thrown objects - like baseballs. Trace the path of a baseball as it follows various trajectories. Your vision ability when hitting is vital. Be sure to get regular vision checks. The better you can see the ball, the better you will be able to smash it!