When I think about how to develop tension in a story, I think of the stories I’ve read that create a sense of anticipation in the resolution of a story element. Tension can be raw and primal, like the tension between the great white whale and Captain Ahab, or it can be subtle and somber, like the tension in “Flowers for Algernon.” There are many kinds of tension an author can employ, but for any of them to work, the tension must be compelling. And what makes tension compelling is consequence. When the story element is resolved, the character or characters involved must cross some line, and their lives should be forever altered. For better or worse, there is no turning back.
It is the anticipation of the consequence that drives the tension. If you want to create truly compelling tension, you have to make the consequences clear, and make them matter to the character or characters involved. The more characters involved, and the more severe the consequences, the higher the tension can be driven.
A good story will have multiple, simultaneous narratives, each with its own conflict and tension. Just as plot lines should intersect and diverge, tension also should rise and fall. A story should have a rhythm, a cadence, a variation of pacing that gives the reader a chance to absorb the story and increase the anticipation of the final climax.
Foreshadowing is one way to promote the anticipation necessary to create compelling tension in a story. But if you want to really push your tension to maximum levels, you should have the resolution of minor tension create new and more powerful consequences for the major tension you are developing. Ideally all of the tension should eventually coalesce into the final, dramatic resolution of the major conflict of the story, delivering all the resolution the reader has been hoping for, and tying the entire story together.
That all takes careful planning. It’s harder to do if you are a “seat of the pants” writer, than if you work from firm outlines and stick to them. When I am editing my stories, I look for any opportunity to adjust story elements to weave the plot more tightly. I do the same for tension, tweaking scenes and tying elements together so that every scene contributes something to the major elements of tension, driving the story to the ultimate conclusion where that tension is finally released.