Note: All of these steps have been tested with the Windows Update (version 1903) and the Windows 10 October 2019 Update (version 1909).
In either case, clean install or upgrade, use this checklist to make sure you've covered some important bases that aren't part of Windows Setup. After about an hour (more or less, depending on the underlying hardware), you should be back at work, with most apps and settings migrated successfully. If you're setting up a new PC or doing a clean install of Windows 10 on older hardware, follow the instructions in How to set up a new Windows 10 PC perfectly in one hour or less.