Choose one plot or idea. Generally a short film script is around 30 to 40 pages, so it should focus around one major theme or event.
Think of your favorite movie and what the whole conflict or purpose of the movie was, like finishing the race, getting the girl, or finding the money. That conflict or purspose is an example of how a plot works in a script.
Without a plot, your idea isn't going to take you anywhere.
Ask yourself these questions: Who are my characters and what are their purpose? Every great film is produced with people involved and each person on screen has a purpose. Jane is after getting a big promotion, but John keeps getting in her way because he too is in the race for a bigger office.
Meanwhile, Brad is already cleaning out his desk and plotting his revenge on the third floor. He knew Jane can't resist a new pair of shoes, especially if they're on sale. And, John plays volleyball on Thursday nights before going out with his favorite lady.
See where we are going? Who your characters are drive who they want to be, and determine their actions.
Outline and create several scenes. Each scene is a transition in the short film. Like your characters in a restaurant, being stuck in a crowd, tied up in a burning building, etc..
Once you have your idea, plot, characters, and potential places of events (scenes) it's time to develop your dialog and create action amongst your characters.
What would Jane say to John when she find him snooping in her desk? Or what would John say to Brad if they came upon each other on the street? Even the sales lady at the shoe store where Jane gets her designer shoes has a line or two to say before Jane completes a purchase and heads off to work.
Now start writing! Take these ideas, scenes, characters, and potential actions or encounters and start putting them together using formulated computer software made for writing scripts or screen plays.
There are several different types of software you can find online for free to help get you started.
(See RESOURCE section below for free software links.)
Join FRENZY - April is Frenzy month for writing short film scripts or longer screen plays. This is a great way not only to motivate yourself into writing a short film script, but to network with other writers who are trying to accomplish the same thing with different ideas.
(Link in RESOURCE section below.)