For this image of Kaaterskill Creek, I knew the small cascade was my main subject. There were some rocks to create interest in the foreground, and the water creates a nice leading line back to the cascade in the middle ground, and then to the foliage in the background. EOS 5D Mark III with EF 16-35mm f/2.8L II. I was zoomed into 35mm on this one. Exposure was 1.6" at f/20, ISO 100.