Read other scripts and watch a lot of movies. Start with films you like or admire; read the screenplay and then watch the film. Make notes on what appeals to you. Notice usage of dialogue, and how places, people and events are visually represented or written about, and how these aspects translate from paper to screen.
Step2
Carry a notebook and start keeping track of your ideas as they come to you. Write down anything and everything!
Step3
Make an outline. Start with an outline on your story, the sequence or timeline of events, story and character climaxes.
Step4
Develop some character sketches. Get to know your characters through some creative writing. Imagine their back-stories, who they are, what drives them and what they believe in or want. Even if these elements are not directly in the screenplay, they can help you develop your characters’ personalities and make them more believable.
Step5
Write a treatment. A film treatment is like a short story version of your screenplay, but longer and more detailed than an outline. Writing a treatment can help you to focus and develop more details on the story and characters in advance of writing the full script.
Step6
Get a scriptwriter program like “Final Draft.” This program automatically formats your screenplay as you write.