At Art College I remember we did the lovely standard exercise where we drew the spaces around an object. This then revealed the object more clearly than drawing the outline of the thing itself, precisely because it by-passed the preconceptions we might already have about the object's shape. The Chinese philosophers and Zen calligraphers urge us to pay attention to what is missing,
Thirty spokes on a cartwheel
Go towards the hub that is the centre
- but look, there is nothing at the centre
and that is precisely why it works!

If you mould a cup you have to make a hollow:
It is the emptiness within it that makes it useful.

In a house or room it is the empty spaces
-the doors, the windows that make it useable.

They all use what they are made of
to do what they do,

but without their nothingness they would be nothing.

Tao Te Ching - Man-Ho Kwok, Jay Ramsay, Martin Palmer Translation.

Sometimes it is more effective to describe something in terms of what is not there than in terms of what is. A setting could be described in terms of what is not there instead of what is. This is particularly effective with describing characters too; what is missing from their personalities can be what makes them what they are. Describing what is absent taps into the lack that lies at the heart of us, and so draws the reader in.