Get inspiration from your own fears and phobias – if it scares you, the chances are it will scare a good proportion of your readership. Primal fears go to the very route of who we are and can be particularly effective if they’re magnified or exaggerated for the purposes of your story.
Short and Sweet
Use short sentences to keep your prose tight and efficient. This will help create tension, whereas longer, description-heavy passages will slow down the pace. And if you’re writing a novel, keep your chapters short. Not only will this crank up the stress, readers will be encouraged to read more of your book!
Keep readers guessing by leaving each chapter or scene on a cliffhanger of some sort. It doesn’t have to be one of your characters in a life-threatening situation each time, but you should aim to have your readers wanting to know what happens next.
Found at: http://www.bbc.co.uk/dna/getwriting/module21p