Ok, you’ve chosen the correct bat size and weight for your needs so now you need to know how to hold it properly. The grip is very important because an incorrect grip can inhibit the flexibility in your wrists and keep them from rolling over smoothly when swinging or result in an insecure grip on the bat. A bad grip will result in poor hitting.
As with other aspects of hitting your grip is a personal preference but there are certain fundamentals that you need to be aware of. First of all, your dominant hand will be the top hand so if you’re right handed then your right hand will be on top of the left hand on the bat. Pick up the bat and lay the handle across your top hand where the bottom of your fingers meet your palm. If this isn’t comfortable then move the bat very slightly toward the fingers not toward the palm. Close your grip with your thumb at your top finger. Place your bottom hand on the bat with the handle at the same place where the fingers meet the palm but slightly more toward the palm this time. There should be very little or no space between your hands. Too much space between your hands and your wrists will not roll over properly. Many will say that your knuckles should line up but ideally the second knuckles of your top hand should be just about between the second and third knuckles of your bottom hand.
Should you choke up on the bat? Choking up occurs when you move your hands up the bat handle. Most commonly hitters keep their hands near the knob at the end of the handle. Choking up a little will shorten your swing giving you better bat control. Barry Bonds and Pete Rose both choked up on the bat when hitting. Also, you may not normally choke up but during certain hitting situations you may want to in order to control the bat better.
Keep your grip relaxed. The great hitting instructor Charlie Lau said, “The most important thing about finding your grip is to remove tension. Anything you can do to take tension away helps, because tension destroys a hitter.” So, don’t grip the bat too tightly.
Here’s a good video showing the basic grip…