Get the Support of Local Bands.

Before you book a gig in an unfamiliar town, seek out the support of a local band to open the show. You'll want a band who has a good draw, but doesn't play to that particular market too much, as many local bands tend to do.  Do your homework on this one and find out just how many people they draw, how many people are on their mailing list, if they've played recently, and if they have a street team to help promote the show. You may also want to find out if they know of any other local bands that would be a strong addition to the show.

Your opening band can do a lot more than warm up the crowd for your ear-splitting set: they have the benefit of living in a town that you're only visiting, so they can flyer the heck outta' the place and promote the show to neighboring markets as well. More promotion equals more people at your show! 

Offer to pay the band back by supporting them the same way when they roll into your town. 

Rock on!