In the late 70s I knew a guy who worked mall art shows who'd paint a painting using only a pallet knife. His gimmick was painting it upside down in 20 minutes. When finished, he'd turn it over and get a good reaction from the crowd watching him. That was followed almost immediately by a sale. The buyer had a story to tell with the purchase.
At the same time I saw another artist do clever presentation. "Ron Art" set up in small malls for three or four days, painting under a mirror so the audience could see. He would paint to cool jazz and do a painting on a piece of hardboard in 10 minutes...if he took his time.
He had a flare for showmanship as his overalls were covered with paint and his paint pots had huge build up of paint on the edges. He was a cool black dude doing his thing.
His paintings were garish, done in bright colors and massive bad taste, without a shred of artistic merit but the locals, having seen them created in front of their eyes, would pop for them almost as fast as he could produce them. Rons talent was in separating the locals from their money.
He made enough money to support himself and his family and to hire a guy to tear his display down and drive it to the next mall and set it up while he flew home to be with his family.