Begin with visitor intent
List the people who will use the site and the questions they need answered. A useful brief explains what visitors should understand and what they should be able to do.
Separate content from functionality
Map the required pages and their content owners. Then list behaviours such as forms, search, account access and integrations. Each behaviour needs a definition of success and failure.
Plan the operating model
Identify who will publish updates, maintain the hosting and respond to enquiries. Agree who owns the domain, source code and accounts. Include accessibility and performance expectations in acceptance criteria.
Agree how the work is accepted
Use representative visitor journeys and devices for review. Test unsuccessful form submissions and integration failures as well as the happy path. A clear launch checklist should include redirects, backups and a rollback decision.