Whenever I get stuck working on a script (which is often), I remind myself of the only two things that matter:
Screenwriting is that simple.
You can find a way to make any story beat more visual. If you’re stuck, ask yourself — what’s the silent movie version? (that’s Mamet’s advice) — how can I see what I want to say here.
And every story beat should be emotional. That means it matters to the characters, on a gut level. And we should empathize enough with the characters that it matters to us. So if you’re stuck, ask yourself — what matters here? why? how can it matter more, and more, and more …. Emotion can be fear or anger or love or contempt or pride or despair or — whatever matters to them and to you and to us.
Then repeat these steps a bunch of times, and you’ve got a script.