1. set up social media for your art and do your research on what hashtags you should use and what is the best time for posting. instagram and twitter are important
2. follow other people and comment under their art but comment like you mean it, not like a bot. and dont like 50 pics in a row, it has to be "organic" for the other person to consider following you back
3. keep a consistent style, if you suddenly change the subject or style you will lose followers
4. have a personal website (you can do a good one since youre a webdev) - make it look professional but not too boring, showcase examples of your art and make it clear you're available to clients
5. be active in facebook groups, i managed to get a few big commissions by being noticed there
6. make sure your art is "usable". it needs to git into magazines, books, whatever you like. it cannot be weird irrelevant stuff that nobody needs. thats why you shouldnt post ref studies, nobody cares about these. concept art and imaginative work counts.
7. write emails to local magazines and publishers, maybe they need some simple illustrations. look out for independent artist groups that create zines and try to work with them.
8. take part in competitions and send your artwork to indie galleries. even caffes are willing to hang your work on the walls and sell it if you give them %.
9. if youre brave enough set up a youtube channel or a twitch stream and come up with interesting ideas for live drawing. you can draw a current trend or try to illustrate something.
10. fanart and porn are well paid, if you're interested then go ahead. i dont know about porn, but fanart does well on tumblr.
a lot of this depends on pure luck and being noticed. if you keep shilling your art and keep a steady improvement you should be able to earn a stable income in about 2 years. being a graphic designer is a "safer" option as you can get hired in a studio and more people are looking for logos, posters than for illustrations.