It's not an unreal aspiration to make money by selling your oil painting artwork or watercolors, but it will take a significant amount of work in two areas:
1) Your art. While it is possible to make money off of art that isn't particularly good–we live in a society, remember, that paid actual money for "pet rocks" in the 1970s–it is easier on your conscience and your marketing plan if you start with a product that you know is really, really good and that you believe in. Do whatever it takes to become really, really good, while still recognizing that this is a process that never ends.
Does this sound obvious? It is, but that doesn't make it easy to see. I have talked to far too many artists who think they are better than they are, and who have huge gaps in basic skills on how to paint that they compensate for, but never admit that they have them or take the necessary steps to address the lacks.
2) Your marketing. I know. You're an artist, not a marketer. But if you are going to get your work out in the arena where people will see it and purchase it, you will have to think about marketing. The good news is, you don't have to start out as a genius in this area and you'll get better as you go along.
As with any project that seems overwhelming upon first view, break your marketing plan down into little pieces, and start local where you know people and have contacts. Our very first marketing move–after we were sure that we had something really, really good to offer–was approaching the gallery in our small town where we knew the gallery staff, because we ran into them all the time in the grocery store (in a small town, this is a central meeting place).
I called the head staff member, made an appointment to bring by some of the Norwegian Artist's work, and answered her various questions. Because she wasn't a total stranger, I didn't feel nervous, and this one small move, in addition to securing our first gallery location, was great "practice" for the next move.
What was your first marketing move for your art? Leave a comment and let me know.