I worked full time in Mechanical Engineering/Design for 18 years before trying my hand at being a full time artist. Its not easy and I have had some disappointments along the way. There is a lot to contend with, such as travel and eating expenses, commission fees when selling, exhibit entry fees, marketing and advertising expenses, etc. So I changed my approach a little - I currently make more money with a painting frame business I set up to offset my shortfalls with selling my actual art. In the end I pulled out of the gallery scene, which often wanted as much as 50% of the sale. I have limited myself to a few choice associations: Oil Painters of America, Salmagundi Club and Lyme Art Association in CT, which still gives me some exposure in the group exhibit arena.
You can self promote online, but that can be an art in itself. There are a lot of artists online... many are excellent - some are mind blowing excellent... and competition is tough. When promoting yourself online you have to contend with things like the search engines, which will introduce you to other things like "search engine optimization" if your developing and coding your own website.
Try to develop of good social media presence if you can. Create account on sites like Facebook, Google+, Twitter and Pinterest. LinkedIn is a professional social network - I'd recommend setting up an account with them.
(P.S. This topic is a huge one and the landscape is always changing so you have to keep current, especially when doing things online. For example, when I started in social media Google+ was a huge thing and Pinterest did not even exist. Now I think Pinterest has more to offer than Google+.)
Last edited by johnok; 11-11-2016 at 12:34 PM.