Secret #1: most moderators are truly terrible. Start there. A great moderator can turn an OK panel into a very good session.
Secret #3: everyone >wants< to be on "the main stage". but want they >need< is to be on a packed stage.
Secret #5: a smaller event that is packed is much better than a larger event that isn't. much, much better.
Secret #7: have a shorter event. no one wants to go to a 3 day event, or even a 2 day event, with rare exceptions.
Secret #9: if you think it's a cookie-cutter event, so will they.
Secret #10: never let anyone talk about their product on stage.