I'm assuming you are using crow and owl calls or a tape of the same? An owl decoy placed in a tree (sorta hidden) works good to hold their attention. We have placed the dead on the ground with wings out and others with wings folded (standing crow...kinda). Honestly, if you just use the calls or a tape, you probably wont need to decoy. We often call in 25-75 birds at a time, always try to shoot the first ones to come in. Once you have a bunch circling and setting in the trees, a few shots will run them off pretty quick. Just pack up and move to a new spot 1/2 mile or so away, or wait about 30 mins and start it back up where you are. They will eventually wise up to you though. Good luck.
A scalpel can be just as effective as a broadsword
Obviously, Occam was not a reloader