It of course goes without saying that symmetry is quite scarce in natural settings, so I decided instead to use my front lawn and the façade of my house as the landscape. Its stairs leading up to the front patio are quite symmetrical, so this is what I focused the image on.
The symmetry of the image comes from the two shrubs flanking the patio, as well as the centered stairway leading up to it. The lighting also enhances the feeling of balance and symmetry, as the darkness works to hide the more uneven parts of the lawn and the light works to accentuate the rectangular doorway.
I think that this photo is effective and atmospheric.