As someone who was raised in the arts I have a special fondness for the abstract and expressionist image. Photography, oddly enough, lends itself to this surprising well. We make a photograph by focusing in on a minute speck of time and space, to the exclusion of everything around it. What could be more abstract than that? We only think we recognize the trees and clouds. So I really enjoy looking for the image that has abstract, painterly qualities in itself. Like the one above: it's the side of a steam locomotive, painted in a brilliant orange, shot just above the drive wheels. By excluding the obvious and peering in on just color, line, and composition, I ended up with something that, to me at least, holds more visual interest than a simple picture of an engine.
I always have, at the very least, my iPhone with me, and often as not even my mirrorless little Fuji camera. There's never an excuse not to constantly scan horizons near and far for art, fine or otherwise.
That little voice in my head is telling me (among so much else) to pay attention to everything, the big and the small. You never know what you'll see, but I bet it would make for a great photo.