One of the most important promotional tools that a motion picture studio can create in a film's marketing campaign is the movie trailer. A teaser trailer can often be created months or years in advance of production to generate awareness with little but a script, and subsequent trailers can be cut and shown during different phases of the campaign. A movie trailer can last anywhere from 60 seconds to two and a half minutes in length and is typically edited from the most visually-exciting footage. A horror film trailer must create a tense and frightening tone with ominous music and startling footage to grab the audience's attention and draw them to the film.
Read the film studio or advertising agency's creative brief to understand the direction in which the film should be positioned. Read the film's script or view footage or production clips to generate ideas and understand the premise of the film. Look for scary and startling clips in the film, and take note of their time code position so that you can find them when it comes time to edit.
Write several short scripts to be read by a voice-over announcer, and use them to set up the scenario of the trailer. Create frightening copy that hints to the carnage that lies ahead without giving away the film's actual ending. Play on the psychological aspect of fear that you cannot see. Submit the ideas to the marketing head to approve one or more of your scripts for production.
Work with a film editor or cut the clips yourself in professional film editing software. Read the voice over script to get a feel of how it fits within the film segments and lay it as a scratch track to be replaced by a professional voice over announcer. Create disturbing and startling visual effects with a graphics program and insert them between the clips. Record an ominous or frightening music bed that will play behind the footage.
Hire your voice-over artist and book time in a recording studio. Work with him to read the script as you created and perceived it. Ask him to use a frightening, hushed and low tone to his voice. Record multiple takes as necessary, ensuring that the timing fits within your previously cut footage. Replace your scratch track with the professionally announced voice.
Add final graphics or title cards, special effects, studio logos and star billing to the trailer. View the entire completed horror film trailer to ensure that it creates a spine-tingling advertisement that piques the audience's interest.
Show your trailer to test audiences and get their comments. Revise your trailer with their opinions in mind, understanding that horror movie lovers truly know what they want to see in a horror film and are the best gauge for the success of the film.