One important point, in my opinion, to build a little bit on what Tennessee Beast said, is that Saturday-Sunday events may not be especially attractive to many homeschoolers. They aren't for my family, anyway, because no secular event on Sunday can take precedence over going to mass. Now, people might respond to this along these lines: "our two-day events are already so inexpensive that there's no problem with a family signing up for such an event but skipping day two." But you need to keep in mind, before making such a response, that homeschooling families are generally living on one income in a two-income society, and (not always, but in my experience more often than in the general population) have multiple children. This tends to make homeschoolers (again, in my experience) rather thrifty. The idea of dropping a bunch of cash on a two-day event, and then skipping half of it, is unlikely to appeal. So in my opinion, doing non-Sunday events is key. And even better than a Friday-Saturday, in my opinion, is a Saturday-only event. It's hard to find two days running to do a big family event. One day is much more manageable.
Along similar lines, providing loaners is key. I mean, many loaners. And this must be communicated in the marketing. Of the families in my local homeschooling group, only a very few are gun owners, and those who are gun owners would tend to own something like an LCP, not something like a 10-22. Equipment issues keep a great many people from even considering an Appleseed beyond the standard "oh, that sounds great. I should do that someday."
Obviously, libertyseeds avoid both of these problems, so they're a great idea. I'm just talking here about events that involve shooting.