Psychological horror films employ various conventions to unnerve audiences through unsettling sounds, slow pacing, and an emphasis on psychological harm over graphic violence. Common techniques include contrapuntal sound, close-ups to convey character emotions, flashbacks to reveal a killer's motives, and settings like abandoned buildings that create isolation and tension. Children and ordinary people are sometimes used as killers to disturb audiences by subverting expectations. The goal is to reveal hidden truths about characters and unnerve through mental states rather than gore.