The Nuts and Bolts
A trailer should be a short video (ideally 45-60 seconds long) that reveals the most interesting and captivating aspects of your soon-to-be-produced feature film, with the intention of grabbing as many viewers as possible.
A trailer is no time to be cavalier (save mystery, vagueness and subtlety for a teaser). Make the trailer strike hard, strike fast, and with no mercy. Showcase snippets of the best action sequences, the biggest explosions, the most famous celebrity talent, the funniest scenes and the most interesting — if not irresistible — aspects of your feature film.
For example, if you are making an action-based feature, taking a crescendo approach for the trailer is a great way to leave viewers awestruck. That is, start at a steady pace but keep building and increasing intensity in volume, visuals and pacing until it reaches a fever pitch, ending with an explosion of sight and sound, then quickly and quietly dissipating to perfect calm, allowing the viewer to finally catch their breath.
For a comedy, the most critical goal is to