1. The fatal sigh. Character is running away from Jason Freddy or whoever the fuck it is, thinks they've gotten away and sighs very loudly with relief. That's when they get grabbed or the axe comes through the door, etc.
2. Creepy kid chanting
3. Killers who get shot, fall out of very high windows, get stabbed, etc. and it doesn't even slow them down
4. Abusive parent, especially if it's implied the killer became a killer only because they had an abusive parent and/or the abusive parent is also a religious fanatic
5. Female sexuality being punished by killer
6. Weird looking doll
7. Masks
8. Clowns
9. Psychics (unless they turn out to be frauds, but you rarely see that in movies)
10. Victim can't see the killer but the audience can
11. Blood coming out of faucets, walls or anything else not alive
12. Black guy getting killed and the other characters not seeming to care
13. Disabled character getting killed in a situation where a non-disabled person would be able to run away
14. Killer seems to appear and disappear silently through camera angles, especially if killer isn't meant to be any sort of supernatural force
15. Jump scares
16. Useless scientists
17. Grossness as a substitute for actual scariness
18. Cell phone not working