Determine the structure of your screenplay. According to screenplay workshop instructor Michael Hauge, screenplays have six stages of plot structure: The setup, the new situation, progress, complications and high stakes, final push and the aftermath. Consider how your story's structure can be adapted to fit the typical structure of a screenplay. If you prefer, rearrange the stages to adapt your own personal style.
Choose characters and plot points in your story that are not important enough to be included in the screenplay. When adopting a novel to a screenplay, length can become an issue. Unfortunately, unnecessary characters or events need to cut out. Decide which scenes in your story will make visual, cinematic scenes once the story is adapted to a screenplay. While some scenes may draw a reader's attention, they may not draw a viewer's attention.
Begin the screenplay with a scene that draws the audience into the setting of the story. Reveal the everyday life of the main character and establish identification between the audience and your hero. By making the main character sympathetic, funny, likable, or unlikable at the very beginning your audience will begin to care for what happens to the character
Start the action of your screenplay by presenting your character with an opportunity early on in the story. This opportunity may be one that doesn't arise in the short story or novel until further on, but for the sake of the screenplay rearrange events to present the opportunity early on. This opportunity is met with a challenge, what Michael Hauges' calls the "change of plans." This change of plan may require you to change the history or geography of your story in order to support the screenplay's quick pace.
Fill your next section of the screenplay with progressive action that shows your hero working to get what they want. This may be a long drawn out section in your story or novel, or it may not exist at all. You may be required to create more plot or conflict in order to lead viewers through this section of the screenplay. Remember when writing a screenplay to support the visual aspects of your story. If you must, create new windows for your audience to gaze through.