The following RFCs define the best practices for DNS Setup.
RFC 2219 – Use of DNS Aliases for Network Services Added to the above the following pointers are also helpful:
Use correct email address of the responsible person for a zone / Domain on a DNS Server
The responsible person email address field on a SOA record should be update and appropriate to date. This field is used by various applications to notify the administrator of various issues like query errors, incorrect data returned by a query and security problems. Also, care has to be taken to ensure the @ sysmbol used in standard email formats is changed to . on the SOA records. For instance, firstname.lastname@example.org should be entered as admin.itsyourip.com
Use of CNAME or ALIAS records
Avoid using CNAME records where they are not needed to alias a host name used in a host A record. Also, ensure that any alias names you use are not used in other records. For example, if you want to use a CNAME RR to support an alias name of "example.itsyourip.com", you would not use the first name label ("example") in other records for the "itsyourip.com" zone. Microsoft Documentation says, Alias (CNAME) resource records are also sometimes called canonical names. These records allow you to use more than one name to point to a single host, making it easy to do such things as host both an FTP server and a Web server on the same computer. For example, the well-known server names (ftp, www) are registered using CNAME RRs that map to the DNS host name, such as "server-1", for the server computer that hosts these services. CNAME RRs are recommended for use in the following scenarios: When a host specified in an A RR in the same zone needs to be renamed. When a generic name for a well-known server such as www needs to resolve to a group of individual computers (each with individual A RRs) that provide the same service. For example, a group of redundant Web servers. When renaming a computer with an existing A RR in the zone, you can use a CNAME RR temporarily, to allow a grace period for users and programs to switch from specifying the old computer name to using the new one. To do this, you need the following: For the new DNS domain name of the computer, a new A RR is added to the zone. For the old DNS domain name, a CNAME RR is added that points to the new A RR. The original A RR for the old DNS domain name (and its associated PTR RR if applicable) is removed from the zone. When using a CNAME RR for aliasing or renaming a computer, set a temporary limit on how long the record is used in the zone before removing it from DNS. If you forget to delete the CNAME RR and later its associated A RR is deleted, the CNAME RR can waste server resources by trying to resolve queries for a name no longer used on the network. The most common or popular use of a CNAME RR is to provide a permanent DNS aliased domain name for generic name resolution of a service-based name, such as www.example.microsoft.com to more than one computer or one IP address used in a Web server. For example, the following shows the basic syntax of how a CNAME RR is used. alias_name IN CNAME primary_canonical_name In this example, a computer named host-a.example.microsoft.com needs to function as both a Web server named "www.example.microsoft.com." and an FTP server named "ftp.example.microsoft.com." To achieve the intended use for naming this computer, you can add and use the following CNAME entries in the example.microsoft.com zone: host-a IN A 10.0.0.20 ftp IN CNAME host-a www IN CNAME host-a If you later decide to move the FTP server to another computer, separate from the Web server on "host-a", simply change the CNAME RR in the zone for ftp.example.microsoft.com and add an additional A RR to the zone for the new computer hosting the FTP server. Based on the earlier example, if the new computer were named "host-b.example.microsoft.com", the new and revised A and CNAME RRs would be as follows: host-a IN A 10.0.0.20 host-b IN A 10.0.0.21 ftp IN CNAME host-b www IN CNAME host-a