The best advice for writing film dialogue is don’t. Never write a line of dialogue when you can create a visual expression. The first attack on every scene should be: How could I write this in a purely visual way and not have to resort to a single line of dialogue? Obey the Law of Diminishing Returns: The more dialogue you write, the less effect dialogue has. If you write speech after speech, walking characters into rooms, sitting them in chairs and talking, talking, talking, moments of quality dialogue are buried under this avalanche of words. But if you write for the eye, when the dialogue comes, as it must, it sparks interest because the audience is hungry for it. Lean dialogue, in relief against what’s primarily visual, has salience and power.
Alfred Hitchcock once remarked, “When the screenplay has been written and the dialogue has been added, we’re ready to shoot.”
Image is our first choice, dialogue the regretful second choice. Dialogue is the last layer we add to the screenplay. Make no mistake, we all love great dialogue, but less is more. When a highly imagistic film shifts to dialogue, it crackles with excitement and delights the ear.