I have step-by-step video guides (with accompanying git repos) for booting NixOS from zero on both Hetzner VPS instances[1] and bare metal Robot instances[2] with nixos-anywhere[3]. I used to use nixos-infect but now I'm 100% sold on nixos-anywhere.

[1]: https://www.youtube.com/watch?v=wr22CyoyRo4

[2]: https://www.youtube.com/watch?v=nlX8g0NXW1M&t=952s

[3]: https://github.com/nix-community/nixos-anywhere