How do you use /goal ?

Guys I was wondering how you use /goal. I usually take my time and use ChatGPT to refine my prompt. It’s usually 50k characters. Then I add /goal to the beginning of the prompt and send it off. But I have seen people saving the prompt to an md file and then asking Codex to set the goals based off of that. I have also seen people only relying on planning. Which do you think works best? Thanks in advance for your time and thoughts.