Slow, steady, and constant education about CostumeCon's existence will go a long way. I had heard OF CC back when it came to Chicago, almost ten years ago now, but I didn't know how valuable it would have been to me - it wasn't until I heard from people who went and saw pictures of the kinds of costumes shown there that I realized "hey! I want to do that!" By then it was finally back in my neck of the woods so to speak.
Honestly, some of the misconceptions about CC and the ICG are tied up with the general misconceptions about how cosplay got started, who cosplays, and so on. There's a kerfluffle in the general forum because some kid dared to tell the 20-something cosplayers that they should stop cosplaying and stop going to cons when they reached their 30s. I can't help but think the only reason younger folk think that cosplaying is THEIRS, the realm of teenagers who like anime and gawd who are these other people who think they can still cosplay when they're old, is because they don't know anything about the history. And even though I chime in now and then, making it my mantra to get them to learn their roots, it's not going to get through their heads without patient, constant education (and lack of shouting). The reason they have strange ideas about CC being elitist or not welcoming to anime cosplayers and so on and so forth is because they still can't conceive of the fact that there are other conventions - other genres - where people dress up in costumes and run around like nerds. They simply don't realize that there are other cons besides anime cons, and that wearing nerdy costumes predated both them and their parents.
Yep I'm starting to be all "back in MY day" and I've only been doing this twelve years. Compared to some I'm still just a whippersnapper myself.
I really think a lot more younger folk - our next generation of lifetime costumers - would come to CC if you emphasize the fact that you will learn hands-on stuff there. And then follow through by making sure the programming reflects that. We can get "cosplay 101" at every run of the mill anime con, so CC should absolutely program a cut above, doing specific panels on specialty topics. I remember CC25 fondly because I learned SO MUCH! Wings and mascot costumes and new methods and specific historical periods and oh my god.
The one thing you're never going to get around is the price. A lot of people still won't go to CC or WorldCon because of the price, and that's when you have to just shrug and hope that someday when they have disposable income they'll change their minds. You can't really get around that. But you can get around all the other stuff with just some education.
Founder and President, Madison Area Costuming Society, a chapter of the International Costumer's Guild
Strange Land Costuming - www.strangelandcostumes.com