Dark underground caves, steep rocky cliff edges, charging packs of Dobermans or any number of arms all have their place in creating tension. Before you introduce these or your better mouse trap exploding helicopter scene make the audience care about your characters.
Give the audience a flaw, a sensitivity, a weakness in your character that lets them identify with him or her. Remember the snakes in Raiders of the Lost Ark?
One of the best ways to create weaknesses for your character is to turn to the 12 defense mechanisms that people use to get through life:
Compensation –strive for perfectionism to over compensate for a weakness.
Conversion – An overwhelming sense of fear manifests as a physical or mental disability.
Denial – Instead of dealing with frustration directly attack other less painful issues.
Identification – Lose a sense of self and begin to identify with those in control or power.
Projection – Put bad traits onto another person who reminds you of the undesirable traits in yourself.
Repression – Exclude from consciousness or memory an event that is too painful to deal with: desires, impulses, and feelings that are psychologically disturbing or arousing.
Suppression – Consciously engage to control unacceptable feelings and impulses.
Undoing – Try to make up for guilty feelings by giving gifts or acts of kindness.
Sublimation – Channel unacceptable feelings into other socially acceptable activies.
Compulsive-obsessive behavior: Escape frustrations through outside distractions; develop coping mechanisms through repetitive behaviors.
Rationalization – Make excuses for other people or yourself.
Addition – Engage in behaviors that are compulsive to reduce anxiety or frustration on a temporary basis. Eventually stops working. Addictions lead to self-destruction. The solution to the original frustration eventually becomes the real problem.
In varying degrees these mechanisms work for all of your main characters—the protagonist, the love interest, the villain, the side-kick, etc.
As you create your character notes try assigning a mechanism or even two to each of your main characters. Use these mechanisms to create complication in physical situations.