Since I'm currently co-creating with a friend, I'm getting used to a more structured process. I used to be very lose about it, thumbing straight away without a clear script outside of what was in my head.
Now, me and more writerly-partner brainstorm a chapter premise, conflict and resolution that pushes the plot. She outlines it, then breaks it into page by page then panel by panel script. I go in and help give some more life to the dialogue (I'm arguably better at character portrayal and interaction but she's much more amazing with plot ans description). We re-organize the pacing so it fits a good number of pages to print run the chapter later. I thumb it out, show her for approval. Then I pencil, ink, tone in stages. Depending on who's more busy at the time the one of us more free will bubble, letter and frame it up. I post it to the webcomic sites.