Writing Dialogue Banter That Works
by Hal Croasmun

Probably the most tempting thing to do in a script is create a scene where two characters banter back and forth. It just seems so easy. You set up some kind of conflict and let them talk.
But does that entertain readers and audiences?
Most of the time, "talking heads" scenes don't deliver anything close to a scene with meaningful action. But they can. For this article, we'll focus on a great scene from GROSSE POINTE BLANK and what makes it so entertaining...for a talking heads scene.

Once you have this, all of your talking heads scenes will be more fun and engaging.
In GROSSE POINTE BLANK, Martin Blank (John Cusak) is a "hit man" who has major concerns about returning to his high school reunion and seeing the woman he left on Prom Night 10 years earlier.
In this scene, he is at Dr. Oatman's office in a therapy session with Oatman (Alan Arkin) and it is a 100% talking heads scene, but it delivers some great drama and comedy.
In this article, you will see four great techniques for improving the dialoge in any scene.
See the full article here.

http://www.screenwritingu.com/screenwriting-articles/36-general-articles/70-writing-dialogue-banter-that-works