So, let's do a little talking about writing process. Since it's what most you probably know me for, I'll start with comics.
The Idea/Outline Phase
Generally, ideas either come to me fully formed or I have virtually nothing in mind but a single scene or maybe just a cool title that I'd really like to use. You laugh, but a lot of writers think of cool titles and then write stories around them.
In the case of an idea coming to be fully formed, I go to the outline phase. I used to be what's called a "pantser" meaning, I wrote by the seat of my pants, meaning, I had a general idea, but was mostly making it all up as I went along. It can be done and it can work just fine for short stories, but for longer works, it's a pain to make it work consistently, so I got into the habit of making an outline and I basically don't do anything without one now.
An outline doesn't have to be terribly in-depth (although some of mine for prose works read like short versions of the work itself) and you don't have to stick to it like glue if you find a better way to do something, but they give you a ten-thousand mile overview of what the final work should look like and that can be immensely helpful in figuring out the details.
Since comic scripts are broken down by page and panel, my outlines are much vaguer and look something like this (not a real comic's outline):
And once I'm happy with what I've got...
I can then turn this outline into a script, like so:
Keep in mind, too, that once a script has been finished, it isn't necessarily finished. Just like any other writing, you should be doing multiple drafts to ensure you're turning out the best possible story you can tell. Having a second set of eyes--an editor, if you've got one or just a friend whose opinion you trust--is invaluable.
. . .
That's the very short version of my process for those who asked. Further questions? Feel free to put 'em in the comments below.