A method for reproducible runbooks: how to write a procedure that works on someone else's machine, months from now, for a reader who has none of your context. Tool-agnostic; applies to any setup, install, migration, or fix you want another person to be able to repeat.
Write for the person who will actually use this: a stranger, on a different machine, later, with none of the context that's currently obvious to you. Everything that's implicit in your head right now — which value goes where, what "it worked" looks like, which shell you're in — is absent from theirs. A good runbook closes that gap on its own: it stands alone, it proves itself as it goes, and it never assumes the reader's environment matches yours.
Each practice below is stated the same way: what to do, the failure it prevents, and the tell — how you know you actually did it.