I recently revised my sci-fi thriller screenplay and submitted it to the Nicholl and the Austin Film Festival. Here are some of the questions and resources that helped me as I rewrote.

• How long does your story last in the story world? I knew my screenplay was 107 pages long, but I had to make a story calendar to figure out we were watching the characters over five days. Before this latest revision, I hadn’t given a thought to whether that number was realistic, or merely convenient for me.
• Are you missing sluglines? When I was first learning how screenplays worked I thought sluglines were scene markers. Nope — they’re there to help map out different locations, and sometimes even individual shots, to help with readability and production. So if a scene happens half inside, half outside, you’d better have at least two sluglines in it. (Further reading: What is a slug?, Sensible sluglines)
• If you cut that scene/page/line, what would happen to the story? It doesn’t matter if the sentences in question are beautiful — if the story doesn’t suffer by omitting it, you should probably lose it. There were a couple times I trimmed an eighth of a page this way, and many more phrases here and there.
• Keeping reading screenplays. One that was particularly valuable for me while working on this current project was Rian Johnson’s Looper. I learned from him that writing the future doesn’t require pretending to be a Flash Gordon product designer. He writes, “Something like a HELICOPTER sweeps overhead” and “…fishes his phone-device from his pocket.” Unless it impacts story, it’s somebody else’s job to figure out what those things look like.
• Watch John August rewrite. I assume you’re already listening to Scriptnotes. Maybe you’ve read his blog. But you may not have found three screencasts he did a few years ago that I found as valuable as anything else he’s done. Watch over his shoulder as he revises three scenes, each with a different lesson: entering a scene, writing better action, and writing better scene description.
• Finally, pay attention to what’s good in the material you’ve cut and imagine your story from different points of view. Your next story might be hiding in the corner of this one.