You don't need to be a writer of the horror genre to include some elements in your book. Some of the techniques even apply to a terrifying episode in a dramatic book. After reading many Stephen King and Dean Koontz books, a common theme jumped out at me. Here's what I think.

The first thing is the stressing of small details. This draws the reader in, and gives the impression that the character's senses are honed. Paranoia, if you will. Depending on your presentation, you want the reader to be confused rather than to make immediate connections. If the reader 'knows' what's going on, the horror loses some of it's mysticism. A small amount of confusion opens the mind up to the unknown. Whether it's a burglar or a monster or a mystical natural force, drop pieces of the puzzle without giving enough for the reader to have the full picture.

One of Stephen King's best stories is "The Girl who Loved Tom Gordon".

A girl gets lost in the woods and relies on her hero Tom Gordon, both as a standard of bravery, and as an imaginary friend as she looks for civilization. She is stalked by something in the woods.

There are really effective moments of dread in that book. You get into the head of that little girl. Short book. Definitely worth a read.