An artist I'm following commented on a specific aspect of how to become a professional. It reminded me of my own attempts at breaking into professional industries of creativity and craft, so I felt like writing a rather long response. It touches on what my experiences have told me about what's "actually" required of you.

The long and short? It's hokey, but if you believe in yourself, and find out what drives you, you will accomplish absolutely amazing things. A much more detailed description is in the link, though. I enjoyed writing it. I hope you find it encouraging. :)