Hello, for maximum yield of sporulation you need to have maximum grow as one cell forming one spore. Better to use reach non selective media like meat peptone agar to have maximum grow about 48 hour than you can put the plate in refrigerator at 8*C for 48 hour to simulate sporulation. After you observe the sporulation by microscopy and see living cells and spores. After refrigerator you will see mainly spores by microscopy. Same you can perform with the use of liquid media. In literature you can see different media which can called sporulation media but all about nothing as one cell can form one spore.