Develop a strong idea. High-concept ideas involving comedy, romance, action or horror are easier to pitch than overly dramatic stories. Dramatic stories focus on character, while comedy and action stories revolve around situations and plot points. Situations and plot points are easier to describe and are more exciting in a pitch than describing a character's feelings.
Open your pitch with a hook. Engage your listener by describing the setup of your movie and your characters. Tell your entire story from beginning to end, informing the major plot twists and turns. Don't describe every little detail of your movie, only the most exciting parts that push the plot forward and reveal character. Imagine yourself pitching a movie trailer and describe your pitch as such.
Write your pitch out on paper. Organize the beats of the story according to the traditional three-act structure commonly practiced in Hollywood. According to three-act structure, the characters and main conflict are introduced in the first act. The conflict is expanded upon and subplots are developed in the second act. The conflict is resolved and the main character achieves his goal in the third act.
Learn your pitch. The pitch is ultimately different from your outline and your final screenplay. It is a selling tool. Learn how to sell. Know your story without looking at your written pitch. You will not need the written pitch if you pitch in person. If you pitch by mail, or over the Internet, you will already have the written version to work from.
Search a listing of production companies that have made movies similar to your idea. The Hollywood Creative Directory is recognized as the industry standard for listing production companies and their personnel.
Attend an open policy event where you can pitch your movie idea. The Great American Pitch Fest happens once a year. Search its website for specific dates.
Register with a service, such as Moviepitch.com, TVfilmrights.com or Makenmovies.com. Submit your written pitches to these services. If your pitch meets approval the principals at the company will "option" the rights to sell your pitch to studios, or studio producers will "option" your ideas outright.
Attend film festivals, such as the Sundance Film Festival, Los Angeles Film Festival, Cannes Film Festival or Toronto International Film Festival. Read the program listings of attending executives and approach them with your idea at any opportunity.