Two things that have worked for me have been using an owl decoy in a tree along with some crow decoys and calling loudly like there is a big fight. Crows like to gang up on hawks and owls.
The other thing that works is crow decoys on the ground and in low trees around a recently dead animal (like a groundhog) or a gut pile. If you pop a few tree rats and gut them in an open area it may give some added attraction to your decoys. I don't know if baiting is legal in VA, but squirrel cleaning is necessary...