I mostly just describe what needs to happen on a scene-by-scene basis. ChatGPT recently introduced a new feature where you can have it remember how to respond to you for every conversation and response. I gave it a portion of TFA script so it’s responses are always in the form of a script.
For dialog, I’m usually a little more direct. You can tell it what needs to be said by a character and it will fill in the blanks on that, or you can tell it exactly what they should say in quotes.
It’s the most helpful for action scenes. Most of the time I just say something stupid like: “They fight on the wreckage, Ben aggressively and Rey defensively” and it fills in all the detail.