Definitely get there early, bring extra layers and snacks, and get ready to recite all the lines with a huge crowd ;-)
Get there early! We got there at 7:15 and we had bad seats. I think we should have gotten there at 6:00.
Bring a jacket and a blanket to sit on. Get there early for good seats.
It was SUPER cold. Next time bring hot chocolate or a sleeping bag. Also get there at least 30 min beforehand to get a good seat!