well there are actual notes on making people more ready for scaring
1. create a sound or music that has things people know but DONT finish what they expect, this makes them think something is wrong, subconsioulsy, and makes them tense.
2. have light EVERYWHERE then suddenly go into darkness and have nothing happen, this makes people think that nothing is going to happen and helps.
3. dont actually have very many things going on so people wont notice something coming up on them, this really helps because it makes you less active, brain wise and when something happens it will cause the brain to be more active, therefore making the blood pump faster and scaring more easy.
4. dont make things happen when you pick something up, do it about 2-5 minuites later, because this reduces tenseness, and when it does happen they will be less expectant.
theres a list of alot