Any time you can mix warm and cool light (in terms of color temperature) you have the possibility of an interesting photo. I was attracted to the cool, blue sky (almost an hour after sunset) and the warm orange light on the grain elevators.
This was a pretty straight forward image to create. I wanted to get as close to the bottom of the elevators as I could and still get the top. I metered the blue sky fairly high in the sky, mounted the camera on a tripod, and positioned the elevators in the frame. Click.
Photo Data: Canon 5D, Canon EF 24-105mm lens at 24 mm. f/8, 8 seconds, ISO 100.