What’s the Secret to Writing Good Horror?

I have recently toyed with the idea of writing some horror stories.  I love the genre and have several story ideas that may have some legs.  I’m just not sure if I can pull it off.  As with everything I do, I try to be the best.  Since we are talking about horror writing, that means I compare my work to Stephen King.  King is the undisputed master of horror, capable of keeping the reader glued to their seat turning pages while feeling true fear and excitement.  That’s a hard act to follow.  Regardless, the hill must be climbed.

The process of fleshing out some of my stories got me thinking about what is required to write good horror.  I didn’t think my work was “scary enough,” whatever that means.  The basic writer’s skill set is, of course, required, but what about more specialized knowledge?  There are no college programs that I know about which specialize in training people to write horror, so how do people learn what it feels like to be chased by a green-tailed swamp monster?  This thought made me wonder if one must first experience true terror before they can accurately write about it.  If this is true, how are there so many horror books available?  Of all the authors who ever penned a scary tale, how many have personally experienced true horror or terror?  Have they been chased by wolves?  Or monsters from space?  Or any other large-fanged villain intent on mayhem?  Unlikely.  So how do they do it so well?

My Google-fu is uncommonly strong, yet I am unable to find any specific, high-quality information on the query.   The summary advice given by the best minds on the subject is to “use your imagination.”  What a letdown.  I can imagine a lot of things vividly, but sheer terror is not one of them.  Even if I could conjure the feelings and emotions out of the ether, how would I know if they were appropriate to the situation?

That’s the rub.  Thoughts and feelings only make sense when considered in a specific context.  Without experiencing the context either directly or indirectly through training, recreating those thoughts and feelings remains a mystery at best, and is completely misunderstood at worst.  Any actions taken with respect to this mysterious context are therefore just wild-ass guesses.

Is it fair to assume that masters of horror like Stephen King and Anne Rice have accidentally stumbled upon the ability to scare the bejeezus out of their readers?  I would hate to believe this.  Unfortunately, there doesn’t seem to be many other possibilities.  What are your thoughts on the matter?