Visualize your screenplay and write it according to what you want your audience to see and hear in your movie script.
Provide a conflict for the drama. A conflict is when something or someone creates an obstacle to keep the other person or thing from achieving a goal. The obstacle is sometimes designed to work against both the hero and the villain.
Read professional movie scripts within the comedy-drama genres. The movie scripts for "Alfie" and "Shakespeare In Love" are good examples of comedy-drama films. To get these movie scripts, go to Simply Scripts at http://www.simplyscripts.com.
Compare the films with the movie scripts. Examine how well the writer of the movie script interprets the film for the director, the cast, and everyone involved to create the movie.
Go to Final Draft at http://www.finaldraft.com. Final Draft software has the tools you need to format your movie script.