I'm a freelance sculptor. I sell my one-of-a-kind sculptures on eBay. I'm not really making money yet, but I'm getting there.
I wouldn't have been able to do it this way if my husband didn't support me, to be totally honest. I have a degree (not in art), but I went back to school at a community college for a couple years to learn some skills and techniques. You can read the long, boring story
here. I haven't made any money for a few years because I've been learning the ropes, but I hope to turn a profit this year. In my case it's a long process.
The bottom line is, if you're going to succeed in any art field, you have to have a lot of drive and self-motivation. As a freelancer, you have to put yourself out there and be willing to market yourself, because it's not likely that anyone else will do it for you. Depending on what kind of art you do, it also helps a lot to know people in the field who can point you in the right directions.
I do advertise on my web site, but that is not nearly enough. "If you build it, they will come" does not apply to web sites.
I am also involved in a sculptors' and collectors' group on eBay; I do link exchanges; I am constantly looking for ways to get my work seen by as many people as possible. It's difficult, because you have to be a businessperson as well as an artist. Business is not something that comes naturally to me. I did take a Small Business class to get some idea of what I was doing. That helped a bit.
Good luck! Seek God, and make sure this is the way to go, because it's not an easy road. But it can be very rewarding if it's what you love.