Study the current trends in movie production, such as the kind of movies considered "hot" at the moment, and the films in development at specific studios. Look for places where your movie might fit -- for instance, a period drama at the Weinstein Company, or an animated film at Walt Disney -- and adjust your pitch to match their expectations.
Develop the idea for your movie. In many cases, you should write a complete script beforehand, though that may not always be possible. Condense your concept into a single sentence or two -- something as enticing as possible -- then compose the remainder to fit within a few paragraphs. Think of it as a speech you need to give and tailor it to fit your particular speaking voice.
Write quick character synopses for each of the main characters like their physical and emotional traits, their role in the story and the arc they follow. Use these in case the people you pitch have questions about them. Attach the name of a well-known actor to each character, so your audience will have a image in mind.
Practice your presentation. Pitches can run between 10 minutes and half an hour, but need to be quick and to the point. Rehearse it in front of friends and the mirror; imagine that you're telling your story around a campfire and holding the audience enthralled with your voice. Give yourself plenty of time to practice before making your appointment.
Make an appointment with the studio or producer to whom you wish to pitch your script. Dress in dark, conservative clothes on the day of your pitch and organize all your materials smartly. You want to look as professional as possible on the big day.