Thinking in black and white...
Choosing photographs at random—barns, stills, people, animals, landscapes—I started experimenting. It's interesting how different images look better with one filter over another (newspaper vs. portrait vs. landscape, etc. Some wash out the background, some make the contrast more vivid. You can use the individual sliders, or choose a preset, or both.
I stayed up way too late, but learning new skills is so much fun, I couldn't tear myself away.