A thing I learned while making a terrible student film 10 years ago
In college I helped a friend, a film student, on a screenplay. The short turned out to be suburban emo horror film student trash, but that's neither here nor there.
After sending my friend a draft of the screenplay that added some excessive nuance, he relayed to me a mantra he picked up from one of his screenwriting professors: Think of Slow Joe in the Back Row. Slow Joe showed up late to the movie, stepped out once to go to the bathroom, stepped out another time to refill his Coke, and has been texting his girlfriend throughout, all from the back row of the theater. If Slow Joe, in spite of showing your work the least amount of respect or effort, doesn't understand the arc of your movie, you haven't done your job as a filmmaker.
Fortunately for moviegoing audiences around the world, that was the last screenplay I ever had a hand in writing. Today I lead product at Figure 1, a case sharing network for healthcare professionals, and I have managed or built several apps over the years, but I still try as much as I can to think about Slow Joe in the Back Row. My Slow Joe isn't in the back row of a theater watching a film; he's using an app on a four year old phone while walking down the street at high noon when the sun is glaring down on the screen and he's listening to music and snacking on a Kind bar. Or he's browsing through the App Store looking for a mental snack while he eats his actual snack.
I don't have any particular method for developing from the get-go for Slow Joe, but it's a useful pneumonic device when planning a feature or a product. "Is Slow Joe gonna get this immediately?" If not, then Joe's just gonna go refill his Coke, and nobody wants to compete with Coke.