Raymond Chandler once said, "When in doubt, have a man come through the door with a gun in his hand."
He was talking about adding tension to a story, of course. I would never doubt Chandler. It worked for him. And I agree, guys and guns most definitely liven up a scene.
But there are other ways to add dramatic elements, too. My personal favorite? The midnight call.
You write what you know, and in real life, I find few things creepier than being woken from a sound sleep by the chirp of a cell phone or worse, the loud ringing of a little-used landline telephone.
You just know there's something bad on the other end. Your stomach knots, your heart starts pounding. But you have to answer it.
I hate when it happens to me.
Even a guy with a gun.