Take your mallet and bat outside in warm weather; cold weather might cause the bat to shatter. Hang the mallet from a sturdy piece of thread, wire, or leather in an open location. Swing the baseball bat and smack the rubber mallet's face each time. After about 20 swings, the bat will have taken on the rough texture of the mallet. This is just one of many methods used by manufacturers to increase the "break-in" period of new bats so that they produce maximum distance and power upon their first use. During this period, you should be able to feel when the bat feels comfortable in your hands as you take practice swings. If it feels too stiff, you should soften it up by hitting some balls off the back fence or taking it to a batting cage for some over-the-wall shots. As your body gets used to the feeling of the bat in your hands, you can start working on your swing. But until then, hold off on making any major changes to how you're holding the bat.