Jon August has a great tip for solving scene and character problems. He calls it "writing off the page":
If you’re having a hard time finding a character’s voice, get him talking about something unrelated to the scene at hand.
Let your hero knock back a beer with his college roommate. Have your corporate spy meet-cute a potential suitor at a ski lodge. Pick situations that couldn’t possibly fit in your actual movie. You just want to get your character talking so that you can eavesdrop.
I use this technique for busting through a stuck scene, or just trying to find the right key notes to hit in a scene.
Most recently, while working through an upcoming scene for The Winchcombe, I sat the two characters down in a room, gave them the topic I needed them to get through, and just had them start talking to each other.
I didn't worry about anything like fitting the dialogue in a panel, or inefficient things like repeating phrases. I just had them go over the topic I wanted them to work through. And eventually, after about three pages of dialogue between the two of them, I figured out everything I needed about the scene.
I didn't even need to refer back to this short document when I wrote the actual scene. I just knew how it was going to go.
Very helpful technique.
Writing off the page