In Adi Spektor’s iPhone-shot trailer, two thieves find themselves robbing the wrong house at the wrong time. The trailer won an award at the Cinephone Festival.

Like any movie, a trailer can be judged by its handling of a variety of  challenges including plot, acting, lighting, set design, and sound. But most important is impact: In just a few seconds, does the trailer make you want to see the movie it previews?