The happening trailer

Camera angles: begin with large range of Mid to long and establishing shots, this sets the atmosphere and scene of the movie, mainly showing the magnitude of the problem.

the further in the movie gets, the more frequent the close ups, this builds tension as it creates a tighter frame making the viewer feel claustrophobic to an extent.

Editing: like most horror trailers, the further in the movie, the faster the transitions between shots, there are a few slow cuts to black, this creates a contrast, as the trailer continues, there are far more fades to black.

Mise en Scene: The mood of the trailer is very frightful in the fact that everyone involved shows extreme worry so the facial expression fits the mood. the environment is usually either crowded with small groups of people, or people cut of in open spaces, which creates an uneasy atmosphere

Sounds: The sounds start relatively normal volume, the dialogue however makes the people involved are worried from the start, as the tralier continues and begins to climax, the sounds get louder and dialogue begins less frequent and more panicked this builds tension, the sounds stop as the title is shown.