Conventions of a horror trailer.

Typically in horror films they are set in deserted places, for example an island, forests, old houses/buildings etc because then the main protagonist who is the target are alone and are not easily helped, which altogether makes the film more tense and scary.

Conventions of a horror trailer.

Also, a convention of a horror trailer is that there is complete silence, and one reoccurring noise which is unsettling and unpleasant to listen to, which makes the watcher more nervous.

Conventions of a horror trailer.

Text always comes up during a horror film trailer, with a sound effect in the background to make it more unsettling and for it to have more of a impact. The text is always in spiky, old fashioned scary font to suit the theme.