Atmosphere
It all started with "It was a dark and stormy night...", which is as good a place as any, but, in the wrong hands, all that will get you is cold and wet. However, when the words are right, and they touch a memory, we find ourselves where the fear lives within us. Which is where we want to be, and getting there was half the fun, wasn't it? Too often, in the rush to tell a story, authors seem to forget that the atmosphere is just as important, and frequently more so, than the make of the farm implement the deranged loony is wielding in the story. Some simply lack the talent to create a moment with their words, choosing to fingerpaint in gore or rely on the overused "jump scare" to carry them through to the next chapter. Which becomes tiresome after awhile, if you ask me. Of course, one could argue that the whole point is to get to the nasty bits as quickly as possible, because, honestly, that's what you're there for. However, a good atmosphere, established early, is in everyone's best interest, for it makes us, the readers, more receptive to the terrors yet to come, and increasing their impact when they arrive. There is a time, a place and a temperature for a good horror tale, and when all those conditions are just right, we eagerly anticipate the sound of the wind fingering our windows, as our trembling fingers turn the pages.