Brainstorm ideas for the script. What is the story about and how will the story progress from point A to point B? Write down all these ideas and then give it a day or two. Come back and reread the ideas to make a final choice on the script you are writing.
Create character biographies for the majority of your main characters. These character biographies should feature personality traits and events in the past that helped show or create these traits. These past events may not be featured or mentioned in the screenplay, but they will help you with your character development and depth.
Write down a basic three-act structure for your script. The first act is a set-up, the second act is the bulk of the movie and the third act is the climax and finale. Each act should end on a significant plot point that brings the movie into a new direction.
Expand the three-act structure into a four-page treatment. A treatment is an expanded outline that details scenes within the movie. The first page of the treatment is the first act, the second and third pages are the second act and the fourth page is the final act. Use this treatment to fully develop and realize your script.
Use sticky notes or a small notepad to write down scene ideas or plot points you want to add. Use this brainstorming process while you write the treatment and it will help expand the ideas of your film and help visualize what you write.
Add "plants and payoffs" throughout your treatment. The plants and payoffs in a movie are crucial tools used to make scenes significant and add a structure to your story. A plant is a plot point introduced early in that story that has a payoff later in the script. Plants and payoffs can be something big or little. For example, a plant early in a story may reveal a person is allergic to bees and in the final act the payoff comes when they must pass a giant swarm of bees to save somebody.
Type the opening scene of your movie script. On the right side of the page, type “Fade In:” and always start every scene with a scene header. Scene headers are also known as slug lines and give the location and time of day. For example: “EXT.: BACKYARD – DAY” is a properly written scene header.
Start and end every scene with a line of action. It can be something as simple as “Joe walks into the bar” or “Sharon starts to clean up the cluttered living room.” Starting or ending scenes with dialogue looks unprofessional and the script will not be taken seriously.