Here are some decoys I made using 3/4" foam. Then, I use a metal coat hanger to stick them into the ground. I usually set about 15-20 of them out on the edge of some evergreens and have a hay day. I use the FoxPro Wildfire II. I've had really good luck in the mornings, just before sunrise and into the morning. They'll come if they are in the area.
One day this first season on them, sometime in November... I picked up my set to go home, made it about 10 miles and saw a group flying... I sped up and cut them off, jumped out grabbed the e-caller and remington 1100, walked 30 yards from the truck and knelt down... Blasted the "Crows 2" call and they turned like a flock of cupped mallards. Picked two of them off that time. Once shot at, they usually tend to fly away.
Good luck, looking forward to hearing success stories from ya.
Ever in the QCA, let me know... I'm always down for a crow bust!