The idea
Begin with the questions visitors need answered: what the business offers, where it operates and how to contact it. Give each page a clear purpose. WordPress pages usually hold stable information, while posts suit dated updates. A simple navigation structure is easier to test than a menu containing every possible page.
Worked example
A fictional repair shop uses Home, Services, About and Contact pages. The Services page lists repair types and links to a contact form. News items become posts. The main visitor task is requesting an appointment, so that action is easy to find on mobile.
Try it
Draw a four-page site map for a fictional business. Write one visitor question and one primary action for each page. Decide which content should be a page and which should be a post.