Decisions decisions =S

Well, in order to make a successfull trailer I needed to get more of an insight into the genre. This started off with watching a number of trailers that were based around the horor genre (which is what my trailer will be) The first of these trailers were everything from saw to the shining. However after more research I found that I would need to look closer at what I was doing... i.e. if I was creating a slasher I would need LOADS of blood but if I was making a more psychological film trailer I would require alot of clever dialogue. Buuuut what should i decide on????