Difficulty: Moderately Challenging
Step1
Outline your entire screenplay in a mini-script format before you've written anything. This particular form of outlining is a brief description of the beginning, middle and end of each scene. It allows a writer to visualize every narrative block.
Step2
Ask the following questions of every scene from your mini-script to determine if the scene is necessary to the story. Does the scene advance the narrative? Does the scene have a clear purpose? Does the scene transition visually to the next one?
Step3
Cut any scene that is not necessary to the story.
Step4
Enter later. If you're running over 120 pages then it's time to trim up a scene's length. A character should enter a scene at the last possible moment, about two lines of dialogue before the purpose of a scene is determined. We don't need to hear small talk. Get to the point.
Step5
Leave earlier. A scene should end with tension so the spectator anticipates what will happen next. Each scene should lead into the next one visually and smoothly. When the business of the scene is over, get out and move on.
Step6
Go over all scene dialogue to determine if it should be edited. Does the dialogue compliment the scene not repeat it? Also, does the dialogue actually come from a character's emotion? A character should not be saying something just to move the story forward. It has to make sense for that particular character's motivation.
Step7
Correct any formatting issues. Make sure all slug lines and names are consistent. Edit any dialogue that is not properly marginated and spaced. Make all character names consistent and use caps properly.