Here's a painting I did of Beethoven a while back. My reference was a wonderful statue of Beethoven in Vienna.
I've tried using oils twice and this was one of the subjects. The oils were water soluble, as I wanted to avoid brain damage. I got so frustrated with the painting, I took it to the kitchen sink and washed it all off. It left a faint blue image which re-motivated me, as it made a great underpainting. The next result, above, wasn't great, as I trashed the painting, but I enjoyed the challenge of giving color and life to the statue image.