Be picky about where the location of your story takes place. The less places to shoot, the better. Most of the winners of this competition had their stories take place in one spot.

Spend more of your time focusing on a good performance from your main character rather than loading your story with a bunch of actors and side plots. You only have five minutes. Let the audience invest that time in one to two characters at most.

An amazing story can be told with little to no dialogue. Heighten the suspense with silence. The scene is no longer scary when people are talking often.

Movies like "It Follows" and "The Ring" were great concept films. If a person has 7 days to live, then they need to die on the 7th day etc. Ideas aren't as original as they used to be. But new story rules can always be fresh and interesting.

The most obvious tip of them all. If you're not enjoying what you're making, chances are the audience won't either. Give it your passion and drive. Everyone will thank you for it!