strips of masking tape and then dark blue watercolor with some salt sprinkled over it. After it dries you take off the tape, paint on the moon with white paint and use watered down blue watercolor to put shadows and lines on the trees.
"Owls in the night" - okay, a little spooky, but still, I think we can turn'em to the "light".. maybe less spooky eyes, but owls have those brushy eyes... more light and snow and a brighter yellow! Yeah, that's the ticket! :)