Many filmmakers, specially the first-timers, want to start with unduly ambitious stories. What makes a short film a great film it's not how ambitious the story is, but the way the story is being told. The ingredients to have a great short film are a coherent script, outstanding directing, compelling camerawork, exquisite lighting and tight editing. There are a lot of films that are interesting, but have a careless sound. Every film directors must care about the sound before the shooting, it's one of the most important cinematic elements. Catch great actors, not models! Stories on screen must be told in a real way, not in a theatricality way.