Haven't done it myself but I think you've gotta promote your art on socials like tumblr and maybe voluntarily Collab with an author or another artist? Link your patreon or take requests by dms.
Then again, I'm not sure if these are right but that's how I got to know good artists who I would've commissioned if I wanted to
I don't do art comissions nor I have ordered one, but I know some that do because of their contents. Maybe you can try making some skit/short video with your art to catch the audience's attention and introduce your art to more people. Then when your contents are getting famous you can promote your art comissions.
It's weird to ask here but I like to hear anyones thought since I've been really having a hard time with money rn