Choose a stable name
Use names that describe a purpose: the main website, an application or documentation. A subdomain can point to a different service. Record who controls domain registration and the DNS zone. Avoid building a public address around a temporary server name.
Match DNS to the service
An A record points to IPv4, an AAAA record points to IPv6, and a CNAME maps an alias to another hostname. Only publish an address family the service supports. Prepare the destination before a change and allow cached records to expire during the transition.
Make HTTPS an ongoing process
The certificate must cover the exact hostname visitors use. Configure automatic renewal and keep its validation method available. Redirect HTTP to the canonical HTTPS address. Check every supported alias: a redirect does not remove the need for a valid certificate on the source HTTPS hostname.