A checklist list of done criteria is helpful to avoid skipping any steps in code creation, this is the list I use for my projects. Where possible automated tools should be used to help verify good practices are followed. These tools are typically language specific so I skipped adding any here.

Ready for Review

• Committed with a good commit message to appropriate branches as determined by the teams source control practices.
• The code works and shows that by being well covered with automated tests, some combination of unit and/or integration tests as appropriate.
• Quality, including:
  • The code has good style and has been lint checked.
  • Simplicity, the code is easy to read and maintain, avoids complexitiy and is focused on solving a single problem.
  • All errors are handled.
• Documented - design and implementations documented in or close to the code as needed.
• Metrics exposed, healthcheck exposed.

Ready for Deployment

• Reviewed and merged.
• Tested in a staging environment.
• Demoed and approved by product owner.

Done

• Dashboards for metrics created.
• Alerts in place.
• Runbook for alerts created
• Documented - All relevant user and administration documentation is in place.
• Live