After reading about the great sale at the Disney Store, I bought a bag full of pins for my kids to trade during our August vacation. Since this is the first time we'll be doing this, what is the proper method? Do the kids just go up to Disney cast members and ask for one of their pins? Do the cast members take one of theirs or are they allowed to choose which one they'd like to trade. Any help appreciated here. Don't want the kids to feel stupid!