Answer
Use Application Configuration Packages (ACP) instead of manual replication — bundle the relevant configuration objects, such as custom fields, into an Application Configuration Package in the source environment, export that package, and import it into the target environment. This is the standard supported mechanism for promoting configuration between environments, commonly used as: develop and configure in Test, add the configuration to an ACP, then export that package into Prod. It also provides a documented record of exactly which configurations have been applied to a given environment over time, rather than relying on memory or manual change logs.