I write scripts based on character motive and interactions. I also make them as detailed as possible so that I can try to translate what I want to draw into panel form.
Hence, a lot of my scripts are in narrative-form rather than your standard movie-script. But it helps me be more flexible with panel arrangement. If I ended up wanting to change something later (be it omit out scenes or add them), I find I can do that easier with narrative scripts than with movie-styled scripts.
It also helps that I color-code my scripts. Here is my break-down of my labels: