Keep a baseball in your bag for the next time you get one stuck in a tree. It's much easier than throwing discs (which might also get stuck) and doesn't take up much bag space.
My Nalgene bottle (best if 1/4 to 1/2 full) works great unless the disc is WAY up there. One was too high, I'd guess 40 feet up, and I literally spent more than 30 minutes throwing sticks and stones. I have a really hard time leaving a disc if it's visible.