Sure, you will eventually need to use the Nix language if you want to have complex and reusable configurations, but this is actually not needed for beginners! To install packages, you need the Nix package manager (with channels already setup) and use `nix-env` to install for the current user. You can just search for the package in https://search.nixos.org/packages and use the command directly.

If you want to have user configurations, use home-manager, just modify the example to add other options, you seldom need complicated Nix expressions unless you need to build a package by yourself.

When you really need to do so, you may want to have a look at other's build script, and make sure you understand everything in the build process, including compile dependencies and runtime dependencies, environment variables, etc. You may want to read Nix Pills at some point, but maybe you can get away with reading just the relevant section (incomplete knowledge, but usually enough to get the work done).

Indeed, I've been using Nix for many years (on Ubuntu, NixOS and macOS), and I now find the apt-get style 'considered harmful'.

Instead, I define a single Nix derivation ("package") which provides everything I want in its 'bin/' directory, e.g.

    with nixpkgs;
    buildEnv {
      name = "my-macbook-programs";
      paths = [ bash gimp /* etc */ ];
    }

For project specific environments, I usually use `shell.nix` (maybe I should switch to flakes now) together with direnv that runs nix-shell automatically when you enter the directory.

For beginners to Nix, I think they should do the transition gradually, there are so many concepts in Nix that may be unfamiliar to them. I think getting a system to work quickly (maybe in a not so idiomatic way) is more encouraging than asking them to read Nix Pills and understand how packaging works in Nix :)

That's actually over-complicated, since I used to use nix-darwin and haven't bothered to un-pick it yet.

What are the advantages of just nix-build, and adding the result/bin/ to path? Arguably, `nix-env --install` modifies the underlying profiles which manage symlinks. (nix-build + add to PATH is imperative invocation; but `nix-env --install` is and imperative invocation with a stateful effect).

e.g. of "how could that be bad?". I'd managed to get myself into a confusing state with `nix-env --install`. When setting up NixOS, I'd installed firefox as the root user. Months later, in my normal user account, I was confused why such an old firefox was installed (since my profile didn't install firefox). I can't remember exactly, but this also somehow caused problems with fontconfig. -- Probably easily avoidable; but if you don't know what you were doing, you might also try all sorts of install commands and forget.