The best release process is one nobody talks about. Merge, wait, done. Getting there is mostly a matter of removing the manual steps that depend on one person remembering them.

Automate the build, the tests and the deploy first. Then add automatic rollbacks, health checks and alerts that tell you something is wrong before your customers do.

Write the runbook with the people who carry the pager. A document nobody on call has read is not a runbook.