You can be flexible here depending on what you have at home, but always make sure to oil your container before putting the dough in. For equipment: For a small batch, I prefer just re-using a plastic takeout/deli container or Tupperware with its lid to ensure it’s airtight. Or a rimmed baking sheet with plastic wrap. Or a 9x13 pan for keeping multiple dough balls with plastic wrap. For larger batches, you can buy a dough box with its lid.