I did this demo for the Lakes Region Watercolor Guild. I was trying to show how loosely I start my paintings.
This is what it looked like at the end of my demo. I made the wheel rim too dark, so I had to scrub it out with a toothbrush when I got home. This is fairly common for me, I often have to get some paint on the page before I see what I really should be doing.
Wheel rim scrubbed out.
I sprayed a layer of mask with a mouth atomizer before each wash on the wheel rim.
I went back and forth, splattering mask with a toothbrush, then painting, then doing it again. By this time, almost everything I did at the start has been re-worked.