Thought, hard work, and proactivity. There are lots of talented artists who will never enjoy a lifetime of working as a successful artist because they don't work hard and don't work smart.
If you want to be a successful professional artist, the qualities that will separate you from the pack are thought and hard work. That's right, good old fashioned smarts. Your average guy on the street wouldn't typically describe an artist as smart or hard working and he'd be right. But a successful professional artist, on the other hand, is usually both of those things.
