I highly recommend trying out a tiling window manager. Yes, they exist for Windows. No, they’re not as good as on Linux or BSD, but it’s a completely different workflow and you won’t know if it’s for you until you try it. Komorebi seems to be a popular choice. I tried workspacer but it was a PITA to configure (I say that as someone experienced in configuring and using a tiler). The Komorebi discord seems to have a channel for sharing configs so you can check it out as a source of inspiration or as a base to build your own config onto.

Also, a package manager like scoop or chocolatey. If I had to return to Windows, this would be a nonnegotiable.

Also, Chris Titus’ winutil for debloating, removing spyware, installing good common software and running a range of tweaks (including disabling or delaying feature updates for better stability).

Vivaldi. Yes, it’s technically proprietary (if you care about that stuff) but it’s really good, if you’re a power user in the browser, or if you’re a tab hoarder. I can’t see myself living without workspaces in the browser now. And the panel is nice if you’re into it.

That’s about it.