Dip into the Working Unit of The Seminars about this business of Visual vs. Verbal Storytelling . Keep your lines of dialogue short. Even in the most play-like of films, dialogue is extremely brief. American films are about what happens next. The technology of cutting from one image to the next has a lot to do with this.
European cinema is the only market for character studies similar to stage plays.
Establish a strong Suspense Plot . Even in a romantic comedy. Film doesn't cope well with the mild suspense plots that work well in plays. If you're unproduced, go for page 1. Keep your scenes short.