Personally, networking in the local area and a bit of craigslist has been what's worked for me the past 3 years.
First year (second round of being indie) was rough, but connections made then have blossomed in to new opps over the past two years. Not sure I can stress that enough - work came to me 2 months ago from someone I met 9 months ago during a meeting with someone else I did work 16 months ago met via Craigslist. I met someone at a conference and 8 months later he called asking if I wanted some ongoing part time work. My own experience is that these things take time, but are eventually worth it.
Not sure if there's a way to go grab the 3 figure hourly rate gigs without personal referrals (I'm sure it's possible, but not been something I've found much). You may want to aggressively let your immediate circle know you're looking for some extra short term / part-time gigs.
Craigslist connections made about 40% of my income in 2008 - it's gone down some since then, but connections made via Craigslist still bring in revenue now and then.
Personal advice - do what you're doing - trim living expenses, shed some excess baggage (unnecessary cars, etc), build up a runway of savings (X months, whatever you're comfortable with) for when you go fulltime on the startup idea. Like many out there, I've got a few of my own 'startup' ideas I may pursue, but want to have a comfortable runway to allow me to focus on the idea rather than cave and start having to do project work midway through the project. Also, just to give myself a bit of breathing space - something I haven't had in many years (though do now, a bit).
http://indieconf.com was set up to bring people together to network and help address these sorts of questions. Virtuality of HN is great, but some face to face to address the realities of freelancing is good too :)
Good luck - ping me at mgkimsal@gmail.com if you care to chat directly.