I’m trying to use Nix again and I would like to know what is the best approach to use it today. Flakes are still an experimental feature? Is everyone still using home-manager?
Although I love Nix I gave up because of the billion ways of doing the same thing and the overall inconsistency, but every time I see someone talking about it the good parts of Nix come back to my memory and I decide to give it another try.
I think this has always been a misunderstanding. There are a billion things you can do with nix, some more polished than others, so if you don’t know what you’re trying to do you may indeed feel like there are a billion ways to use nix, even if you don’t care about 999 million of them.
Nix itself is a relatively simple tool, which is being used in many creative ways in a large ecosystem. This is kind of like not wanting to use bash because it’s used in so many different contexts 
To answer your question, there is one crucial thing you need to tell us first: What is it that you want to do?
Yes.
No, that was never the case.
Are you talking about nix or NixOS? And as asked, why do you want to use nix or NixOS?