All stories are visual. Whether you're watching a movie or telling your kids a bedtime story. All narratives strive to paint vivid pictures in our minds. The best stories, even the ones that aren't flickering to life up on the big screen, are rich with imagery.
The choices and decisions your characters make should be cinematic or "photographable." Film is a medium of action (motion) and imagery (pictures). Action and imagery are the fundamental tools of crafting stories for the big screen. If you're story isn't unfolding through action and imagery, you're not writing for film.
Finding photographable moments in action films, detective stories, and horror films is easy. These genres rely heavily on highly tangible, external (cinematic) goals. Every single film in the Indiana Jones series has a physical, photographable object that Indy is striving to protect or find. In fact the Ark of the Covenant is so photographable it even made the cover of a few versions of the movie poster.
When I was in grad school, my screenwriting professor assigned us an exercise that, at the time, made very little sense. We were tasked with creating a movie poster for the script we were writing. The homework seemed like a throw-away assignment - just a professor trying to kill time in class. I had to write poorly for a long time before I realized just how important of an assignment it was.
More than a decade after taking that screenwriting class, I was preparing to market my first low-budget feature film at Le Marché du Film at the Cannes International Film Festival. The film was a labor of love, a personal piece of cinema that we put together over the course of three years with whatever scraps we found lying around. The film wasn't produced with any sort of distribution in mind. But after finishing it, we didn't want to see our film end up on a shelf somewhere just collecting dust. So despite not having a game-plan, we went ahead and took the film into the marketplace just the same.
We never sold the film.
When we started to put the marketing campaign together we ran into a major problem. What should our movie poster look like? Not one single scene in the film jumped out as a profoundly cinematic moment that defined the film. Not one single image encapsulated the themes and journeys of our main character. I scoured through the footage looking for my "ET and Elliot silhouetted against a larger-than-life full moon as they soared atop their bicycle through the mid-night sky" moment. But as the writer and the director of the film, I had to hang my head in shame as I realized that I never created such a moment in my film.
And so we ended up with what most low-budget independent films end up with - a poster with a couple of disembodied floating heads superimposed over a nondescript background with the title of the movie written out in an interesting looking font that tried to make up for the rest of the poster's lack of originality.
At first it was a lesson in film marketing, but in the end, it taught me a great deal about cinematic, photographable storytelling.
All stories are visual stories, but movies need indelible imagery like our bodies need oxygen. Movies just don't work well (or make any sort of lasting impression) without images that "stick".
So as you're writing your story, consider this: what if your script was going to be reworked and presented as a children's picture book? Would an artist be able to easily find the iconic moments in your story to illustrate? Or would your book just be filled with a bunch of drawings of people talking or performing actions we've seen a thousand times before? Only one children's book would ever have an image of a boy and an alien soaring on a bike through the night sky.
If you had to create a movie poster for your film, is their a pivotal scene (probably towards the end of the film) - a poignant image that encapsulates the theme of your narrative - an image that is uniquely YOUR film - that would serve as the perfect image to convince people that they must see your movie? Don't be fooled into thinking that this is just a marketing ploy; iconic imagery is what movie making is all about.
Back before the days of smart phones, I'd sometimes find myself in situations where I wished I had a camera. I'd see something in the world that made such an impression on me I couldn't help but want to preserve it on film. That's how you want your audience to feel as they watch your movie or read your script.
So as you craft your narrative, create actions and images in your stories that beg to be photographed!