Dress in layers. Watch out for the ogre.
For evening shows: Wear an insulated jacket! Wear socks! Bring cushions for the bottom (&back!) of the plank benches! You WILL get cold & stiff sitting in a stationary position for 2hours...
Parking sucks so get there early and remember to bring a blanket.
During the summer, they have films in the forest. Check out their website! http://www.foresttheaterguild.org