Artists always want to know when a painting is finished. A questioner once asked Wolf Kahn when he considers his painting finished. Kahn said, "When it is no longer a royal pain in the ass to me." Intuitive art is often a process of painting oneself into trouble, and finding the way out again.
I wrote recently about reclaiming sanded paper. I have been taking used paper from my "failed paintings" pile and re-working the images. The great thing I have discovered is that when I start out with a ghost image, I begin the process already in trouble!