The prevailing idea about how to do sound for movies is that you paste sound design and music onto the outside of an otherwise almost finished film. The chances of this working like a charm are not high, though occasionally it does. The much surer approach is to make sound design and music part of the DNA of the film starting with the writing of the script, and to allow creative ideas in the visual and sonic aspects of the film to inform each other from the beginning.
There are certain kinds of visuals and sequences of visuals which swing doors wide open for sound design to collaborate. They roughly fall into two categories…
Visuals with lots of mystery about them, among which are:
black and white images
slow motion images
distorted images
images with smoke, fog, haze, etc.
dark images, or images with dark quadrants
Dutch angles
images that have a strong element of POV
images featuring a strange looking landscape object
extreme close-ups
extreme wide shots
What these styles have in common is that they hang visual question marks in the air which sound can supply clues for, thereby stimulating imagination. Basically, the message is to starve the eye to energize the ear, and starve the ear to energize the eye. Filling the screen with visual information is often not a recipe for great sound.
Visually dynamic shots that allow a sound or set of sounds to evolve, for example:
a wide shot that evolves into an extreme close-up, or vice versa
a shot that traces the movement of something, perhaps an emerging crack in a wall, which moves and grows and evolves
a shot that goes from dark to light, or vice versa … or in-focus to out-of-focus, etc.
a shot in which an object moves through air or space, and changes as it moves
a shot in which a landscape or an object changes in an odd way
What these styles have in common is that they have an arc over time. That arc can be a powerful metaphor.
When a shot has both dynamics and a sense of mystery it is almost always a playground for sound design.