One of my favorite suspense-building techniques is to prolong the inevitable. A quick, readily recognizable example of this is often found in the culminating kiss at the end of a romance novel or movie. For instance, the lovers move together, hesitate, move closer, hesitate again. They breathe, move a little closer,then Dang! They're interrupted! Finally, they press their lips together. Even as I wrote the preceding example, I felt a bit of anticipation. (Grin.) Did you?
Two more examples:
1) In chapter one of my first novel, Missing, I utilize this prolonging technique by having something "soft" happening in the foreground while something threatening is going on in the background. In it, the reader "sees" Stacie Cox singing a solo of "Silent Night" in front of an important audience which also contains the kidnapper and the missing child. Slowly--much too slowly--Stacie recognizes the missing child, but when she does, it's too late; the kidnapper and child have disappeared.
2) In one episode of the classic TV show, Gunsmoke, a family of outlaws imprison Kitty and Marshall Dillon in a cabin while they build a gallows outside. That, alone, created suspense, but the writer upped the ante by having the two captives intermittently and poignantly say good-bye to one another or try to figure out how one could help the other get away. All the while, the incessant hammering on the gallows went on in the background. Since this was a series, the audience knew--yearned for--the characters to get away, but time after time, their efforts were thwarted. The writer had prolonged the inevitable.
Can you think of any other examples? I'd love to hear about them if you have.