What is the secret formula for scaring someone [No cheap scares!]

[Cranky Old Man]

This is a sort of a weird question, because I'm thinking that if you don't know how to scare somebody, then why bother? Why would you want to scare people, if you have nothing scary to tell to begin with? I can respect an Amnesia story that tells a good story without being scary, but I can't respect a story that I know is just deliberately out to scare me.