I have been doing a little investigating online and have found that the best way to build your club is by running rated events that are advertised widely. And in order to do that, you really need some TDs. Fortunately, becoming a Club TD is not difficult--it just takes submitting a simple application. I am going to bring this up at the club next time and make it my goal to get three other members to commit to becoming TDs this year. To support us in our quest, I'm going to build a mini-site devoted to getting TD certification.
I also read an interesting discussion on boosting club attendance in the USCF forums. I think we are doing practically everything that anyone suggested except running more rated events and working to organize local scholastic organizations. We could also be doing more to promote the club simply by distributing flyers at state tournaments and at other clubs.