Funny story. I was rinsing my watercolor palette and a small dried patch of Payne's Gray ink activated in the water as I swirled it around. Lightbulb moment - "what if I put a piece of watercolor paper over this? will it turn out"?  Once it dried, I clearly saw the shape of an eye and a head.  I didn't do any sketches first, just grabbed a pen and drew on an ear.
 
This image was created by transferring watercolor on a plate to archival paper and hand-embellished with waterproof pen.  Art prints are available in sizes 8x8 or 10x10.