Creating an UX Flow (mind-map, flowchart or how you want to call it) is the one of the first things that’s wise to do - maybe even before planning the project. It gives a good overview of what needs to be made (i.o.w.; “how big is the website going to be”) and what’s in the scope. Make sure all pages including subpages (and even the “Form send” - “Thank You” pages) are included so you get good view of all the pages .
A good practice is to number pages (e.q. 01 - “About”, and sub-page: 01A - “The Team”) so it’s clear what a particular page its parent is - this is handy for communication with the client but also for later on during the development phases. On the “pages” you can (if it’s clear) also already add the blocks (or sections) - and number them too. This gives a clear view of what needs to be created and what blocks we can re-use along the website - already during the first step!
The second “layer” we can create is the “User Flow”. This can be done in the same overview as long as you keep it clear to understand - this can be done by using e.g. colours, different stroke types or opacity. Use your creativity to make clear what you mean - for example; it’s a good practice to use short Scrum kinda stories to tell what’s happening on particular points in the map or what route personages use to navigate the website.