Separate the kinds of change
A corrected opening time, a software update and a redesigned checkout are different jobs. Decide who can approve each and how it is recorded. The person editing copy should know where to report a technical issue.
Keep a short change record
Write down what changed, who made the change and how it was checked. Include a link to the relevant issue or release if available. That record can be more useful during a problem than a folder of unlabeled screenshots.
Review the visitor journey
Periodically follow the main paths: navigation, search, forms and key downloads. Use a small checklist that reflects the actual site. Remove or update content that no longer describes the service accurately.