Making your own is an option. It is messy, difficult, and inconsistent. Another option is to find a local ceramics dealer and
purchase Greenware, which is
ceramic that has only been fired once. It breaks well, can be painted, and doesn't leave hard, sharp shards. This is not to say it doesn't still have some issues.
Anything that breaks has the potential to leave behind parts that are capable of cutting or causing injury, especially to the eyes. Several rehearsals are necessary just to make sure debris is not flying towards cast members.