I realized yesterday that I should expand on "Step 2: Pack for Blue Skies" from the previous chapter of this Guide to the Blue Skies Music Festival.
Blue Skies is not wilderness camping. You drive your vehicle to the unloading zone, you load your stuff into a huge cart, you push the cart to your site, unload, and set up. At the end of the weekend, you reverse the process. This means that you are limited only by your budget and how much you can fit in your car.
Here are things I bring:
4 folding chairs that came with the cardtable - Not only good for sitting at the table, guitar players and accordion players don't have to fuss with the arms that come on lawn chairs.
A 6-person tent - The number of people that can actually fit comfortably in a tent is the number of people the tent is rated for divided by 3. A 3-person tent is comfortable for 1 person. Mine is comfortable for 2.
A hammock - You can almost always find a place to string up your hammock and they're just plain fun.