To break in a new baseball mitt, you can follow these steps:n1. Apply a small amount of glove conditioner or oil to the leather.n2. Use a ball and repeatedly hit the pocket of the mitt to soften the leather.n3. Play catch with a friend or use a pitching machine to help shape the mitt.n4. Store the mitt with a ball in the pocket to maintain its shape.nWith proper care and gradual breaking in, your new baseball mitt will become more comfortable and responsive over time.