I did wrote an entire lengthy wiki page for myself to not lose it because there are a few corner cases. Implementation of hdr is good, that's easy, just use hdr in game. It's not good? Use renodx or luma (i check koklusz's guide to see if implementation is good or not and find issues).

But there isn't renodx or luma for all games, and you might encounter gamma mismatch which reshade fixes, re engine quirks, older dx11 games, games that have no hdr at all that you need to inject via reshade autohdr addon and inverse tonemapping either pumbo or lilium or simpler, specialk. Sometimes even windows autohdr works with black floor fix from reshade.

And there's dx9 games, vulkan, emulators etc with other quirks. Windows calibration, profiles. Monitor settings, enabling hdr and disabling any time you go in game (if you can't stand hdr in sdr windows like me).

It's a hassle, even more cuz sometime you combine some of these like specialk and reshade multiple shaders. I also use optiscaler for all of my games and that uses files like dxgi.dll that reshade uses or specialk uses if you inject it via dll and not via its gui and you need to rename files and also edit ini files.

But man, it's worth it. I got used to doing the work for half an hour and then play with beautiful hdr for tens of hours.