I know how hard it can be to advertise. Here are a couple things to try. If some of these ideas are repeats from previous posts I'm sorry I just kinda skimmed through.
Drop some flyers off in grocery stores in their free racks where publications like the Greensheet/Pennysaver are.
Make tear tag flyers and place them on apartment home bulletin boards. (Had a good deal of traffic from that)
Co-workers are great!
Flyers on car windshields. (May have to do this on more then one occasion as I haven't really seeen a good response to this kind of advertising for a one time shot)
Just a few things that came to mind.
Good luck to all!
Jason