Before the change, export or record the current DNS values and TTLs.

Lower TTL ahead of time where justified.

At change time:

  1. update the intended record only;
  2. query authoritative nameservers;
  3. query representative recursive resolvers;
  4. run protocol-level checks;
  5. send controlled test messages;
  6. monitor logs and authentication.

Keep a rollback value ready, but remember rollback is also a DNS change subject to caching.

Reference material