You have to research the hell out of these tournaments. I know it is tough, especially in the early season, but you have to find out who is registered, look them up and see who they have played and determine if it is worth going. I hate MyHockey rankings, but you can at least look up who has played who. And if they aren't listed, go to their website or their league website and research.
Also, have a plan for when you meet with parents after evals. For the most part, outside of AAA and some AA, most teams just do 1 travel tournament a season. If you want to do 2, have everyone vote on it. As stated above, even a simple 2 night weekend away can end up being a lot of money. If you are playing over Thanksgiving or Christmas, make sure people are available.
I think the biggest problem with some of these tournaments is that they really need to start telling teams that they aren't a fit. I know that's never going to happen(except for some of these high end AAA ones) because they aren't turning down money and they need to fill out the bracket with at least 4 teams to make it work.