There's always a child dressed in Victorian clothes, that only 1 person can see when they move into the 'big house' with their family.
The big house always has a locked door upstairs, that no one has a key for. But then one day that door is suddenly opens- usually when there's only the woman at home. Out of curiosity, she enters and then sees Victirian child who explains the happenings .....
If the phone rings and when you answer it, the line clicks and goes dead -run for your life as the psycho killer knows you're home!
Christmas in films, everyone is seated round an enormous table with matching chairs, even when film hero or heroine brings unexpected guest home. No scrabbling in the shed for a garden chair, or lugging the chair from the study for UG to sit on.
They all go outside on Xmas Eve to watch the snow falling. Cos it always snows on Xmas eve night.
If the character is a gay man, they're as camp as can be and have the best one liners.
Everyone in New York lives in loft style or 50th storey penthouse flats, regardless of what they do for a living.
If the character is in a crowded bar, they still get served immediately. No waving a note around for ages, getting pissed off that loads of people are getting served before them.