I'm in the final revision stages of the novel version of The Fempiror Chronicles: The Initiation of David, so in a few weeks, it'll be out there on Amazon for public consumption. That's right, a physical, printed and bound book that you could carry to the lake, if you were so inclined, far away from technology. Some of you may have read the screenplay this is based on, but it's undergone a massive amount of changes in the conversion from script to novel.
Plug:
You can read the Prologue here. If you're curious about what a nilrof is, it has a picture...
I found that through this, I discovered a world of issues that I probably never would have if I weren't forced to think through every single character on the page. It was a process that created a story that was even stronger than it was before, and I imagine as I work through the subsequent stories that "novelizing" them will improve them as well.
So what I can I take away from this experience to apply to screenwriting. Well, what worked here was being the "God" of the story. Instead of the thought that someone else will fix it later in production, I had to paint the world, its people, its colors, its clothes, its processes, and everything else completely on my own. So in the writing of a novel, I had to be the director, prop department, costumer, historical analyst, et cetera, and all that stuff gets to stay on the page because those thousand words are the pictures.
In screenwriting, our job is to write the story and the story only to allow those other people to provide their input and creativity into the process of bringing that story to life. After all, a collaborative effort usually yields a better result than a solo one. But the initial writing of a screenplay is a solo effort, and if you're writing a spec that you hope someone will pick up someday, it becomes all the more important for that script to read flawlessly. The reader has to be able to see the movie play out, except that they fill in their own pictures as opposed to the ones a novelist would paint out.
In The Fempiror Chronicles, the largest single change I had to enact and research was life in the late 18th century. I had to find out the clothing style for men and women and ensure that each character had his or her own style within that style. I had to know exactly how the tailor profession worked in that time period. I had to actually research how shirt dying was acccomplished since the main character does that in his first scene. The screenplay version is waaaaay off. I learned about a mantua maker, even though I'd been using the definition without knowing the term. All of this subsequent research painted a more realistic world for the characters in the book. While a screenplay wouldn't have these details, a lot of this played into the dialogue and storyline more than I thought it would. After all, I never took into account their culture before I wrote the novel. Imagine how much better the script would have been had I done this much beforehand.
For those who do know the story, I actually had to work out what a nilrof looked like specifically and how it would be carried.
What else did I figure out? I worked out a multitude of seemingly incidental things within the story that I never considered because it "worked on screen." Well, take the screen out of the equation and stare at it like a story. I had to rewrite an entire sequence because it didn't actually work. Incidental things such as room layout and character action had to be considered since I'm now controlling them all. There were many times something didn't work because it wasn't actually feasible. There were a load of open-ended issues that I never even thought about before I was forced to write it out in painstaking detail.
I'd like to go into details there, but I don't know how much anyone would be interested in this specifically, so I don't want to bore everyone. Suffice to say that when writing your spec, you need to consider the details that your readers will not read. When you write that first draft, I would recommend at this point being as detailed as possible. Write every single piece of information you have for that first draft right down to the kind of flowers sitting outside the house, if you want. The catch there is that when you have the script where you want it, you have to remove all the extra details and leave only the bare minimums. Or you can simply rewrite your own script as a book to see what it actually looks like. Obviously, you might not be looking to publish it, but what this will show you is all the details that the screenwriting craft doesn't allow you to add. You can plan out your vision for the story in as much detail as you desire without worrying about whether it's "too much." Take what you learn from that exercise and rewrite your screenplay.
After all, when people read your screenplay, they should notice that the details aren't there, but they should be able to feel like they could be.
What was the most significant detail I had to all of a sudden keep track of in my story when I read about the clothing style? I had to keep track of our hero's hat, since that was the mandatory style back then. That detail, which is not present in the current draft of the script, would have to be present in the next because it's part of the culture. That it isn't there shows I didn't know much about common 18th century life when I wrote it.