The first thing I use is Windows 10 decrapifier.
To use this, open up Powershell ISE as an administrator, and paste the script into a new editor window, then run it. It will automatically remove all the garbage Windows 10 installs by default. It works pretty well with Windows 11 as well.
https://community.spiceworks.com/scripts/show/4378-windows-10-decrapifier-18xx-19xx-2xxx
Next, O&O Shutup10
This tool shuts down a lot of the different telemetry stuff to keep windows 10 your own. It also works with Windows 11.
https://www.oo-software.com/en/shutup10
Finally, I like to install OpenShell, a start menu replacement for Windows 10. Right now it doesn't easily work on Windows 11, I use Start11 on windows 11. Openshell doesn't just replace the start menu with a windows 7 style start menu, it reimplements search so the search works much better and doesn't rely on windows search service.
https://github.com/Open-Shell/Open-Shell-Menu
Here's a bonus tip that only applies to Windows 11: If you use the open source tool rufus to create your installation media, you can tell rufus to create installation media that bypasses all the new TPM requirements. I have a computer capable of running windows 11, but I don't want to give them access to my TPM, I don't want secure boot, I don't want any of this stuff. I want to run my computer the way I want to, and this install media allows that. You lose some minor features here and there.