Start here. This is the direct spoken answer to practice first.
Overview
Entity mappings describe application expectations; production schema evolution needs an explicit, reviewable deployment process.
I use versioned migrations through a tool such as Flyway or Liquibase and keep them in source control with the application. Hibernate schema generation is useful for disposable development or tests, and schema validation can check that mappings match an existing schema. I do not use automatic ddl-auto=update as the production migration strategy because its changes are not a complete, reviewed rollout plan.