Kenneth Reitz, a Developer Relations Advocate, shares essential practices for managing PostgreSQL databases, emphasizing the importance of never storing database credentials in the codebase and instead using environment variables like DATABASE_URL for secure access. He advises regular rotation of database credentials, especially during team changes, to prevent security breaches and suggests using BIGINT or UUID for primary keys to avoid storage capacity issues and lengthy migrations. Connection pooling with tools like PgBouncer is recommended for performance optimization, though DigitalOcean provides this out-of-the-box for its Postgres users. These practices aim to enhance security, efficiency, and scalability for managed PostgreSQL databases.