A very common device used in film scoring, especially when writing action music that leads to a climax is to spontaneously modulate up a semitone, whole tone or minor third.
This works most effectively on ostinato-driven music with sparse harmonic movement. Good moments for the modulation are of course the ones that fall together with a dramatic switch in the film sequence as well. There are quite a few action scores which rely on this effect and do it even several times within a cue.
However be aware that an overuse of this technique might become annoying to the audience so save it for moments which truly benefit from this shift upwards.