Absolutely, in fact several artists are already doing precisely that.  All you need to do is pick a work of yours that you think people would be interested in, and submit it to OGA under any of the license choices that we offer.  When you submit your art, be sure to include a link back to your web page or portfolio in the submission.  You may also want to mention in the description that you work on commission.  If you release your art under CC-BY or CC-BY-SA, you can mention in the description that people should link back to your website when they attribute you for your work.