Generally, you'll end up connected to similar guys in your field after you've been running a startup for a while. You can reach out to them and say that you're offering XYZ consulting services in an effort to pseudo-bootstrap your company while still working on improving traction for your company. Most business people will actually really respect that, in fact.

It really depends on how well you've networked though. At the very least, you can start picking up random gigs on Craigslist or even contract work if you have any technical skills to at least keep money coming in in the short term so you can afford some breathing room.