Characters in a horror film are often shown to be isolated, alone or with only few people separated from the rest of the world. This makes them be even more vulnerable to the killer. Often they are also home alone, walking somewhere at night or trapped (this ties in to Craven's theory, that the safest places can be made the scariest). This makes the audience feel displaced and insecure.
Final Girl Theory
That theory talks about how one female character will always be left alive until the end of the film, while all the other characters die. Girls that survive aren't presented as stereotypical naive and 'pretty', but rather rational and quiet.
Phones
Technology in horror films rarely works and that highlights how alone the characters are without any security, making the audience feel hopeless and scared. That represents Caroll Clover's idea of technology never working in a horror film to create another form of isolation and tension.
Playing With Audience Expectations
Building suspense is a big part of a horror narrative, however it can lead to the audience quickly knowing what will happen next and being disappointed. Usually horrors used music and sound to build up to the scene, which made it obvious something will happen. As a result a modern trope has appeared, where the film ignores the typical moments of jumpscares to keep the audience surprised and never know what to expect. Moreover some horror filmmakers try to focus on the psychological fear rather than typical suspense and jumpscares, so that way it will stay with the audience long after watching the film.
An Unseen Monster
Typically in paranormal horror, the killer or monster won't often be actually shown but rather heavy implied on with plenty of references. This adds tension to the film, as both audience and characters never see the threat and therefore they cannot truly expect it. Also by never showing it, the audience tend to imagine the monster themselves which makes the film more interactive and creative. In addition often the paranormal 'possesses' characters, which adds insecurity because it suggest that even our loved ones can attack and also be a threat, not just the unknown.
Iconography
This includes aspects such as lighting, visual style, props and common objects. These are meant to represent evil, danger and blood. To fit conventions they must be typically dark and mysterious, often gore or sinister such as low key lighting that creates dark shadows and unfamiliar shapes in the darkness.
The locations of murder scenes
One of the most common places that murders happen in horror films are at home, in place characters feel safe. Moreso, the scenes often happen in the kitchen or bathroom. The kitchen is quickly associated with knives, whereas the bathroom is where characters are usually private and naked, meaning vulnerable.