Best-practice flake NixOS configurations to draw inspiration from?

I recently switched my legacy NixOS configuration to use flakes, and although I’ve got things working, I suspect it could use some refactoring.

Are there any resources providing guidance (e.g. collections of well-crafted flake nixos configurations, best-practices, …)?

I think your are looking for this: GitHub - Misterio77/nix-starter-configs: Simple and documented config templates to help you get started with NixOS + home-manager + flakes. All the boilerplate you need!