Hard to say … all that really comes to mind is that old joke “How do you get to Carnegie Hall? Practice.” But seriously … I’m not sure. I know that doing well in an audition even if you don’t get the job means that you’ll make it on to the sub list and get some calls that way. But for the non-classical world, there’s nothing similar.
I suppose it’s networking, meeting people, until you find the right musical partners or know enough people that your calendar fills up. Maybe singer/songwriter meetups? Jam sessions (I don’t really like them, but …)? Taking lessons from an established player (sometimes they can throw you a gig you’re ready for when they get busy)?
Good luck! And check out my next few blog posts: about starting over.