We got there about 15 minutes before Wishes was about to begin, and sat ourselves right in the middle of the "street". Soon, everyone was sitting, and we were right in front of the castle, with Tink flying right over our heads. It was wonderful. I held my two sons close to me, and had tears of happiness running down my cheeks.
Go right in front of the castle and see if people are sitting down on the ground. If so, join them!