Start with nothing remembered
Use a clean fixture and follow your own setup instructions from the beginning. Name the runtime version you tested, the command to run, and any required configuration. Make missing configuration produce an actionable message. Do not depend on an untracked file, a secret in your shell history, or a globally installed package you forgot to mention.
Check the edges of the promise
Try empty input, invalid input, and a realistic larger example. Confirm that the output is accurate before checking its appearance. For an interface, verify labels, visible keyboard focus, and a narrow screen. For a script, inspect exit codes and what happens if the output destination already exists.
Make recovery ordinary
Explain where output is written and how to remove it. Keep destructive actions explicit and give users a preview when practical. Write down what the tool does not support yet. Before sharing a build, inspect included files for credentials and private fixtures. A short honest release note is more useful than a long list of intended features.