This is my first year with chickens and, knock on wood, I haven't lost any to predators yet. My neighbours cannot say the same. They have lost a few in the last couple of months. All I do is lock them up at night, make sure they have places to hide when the hawks are overhead, and mark my territory. The latter part is a superstition of mine from my days backpacking alone in remote wilderness. Not sure if it helps, but it made me feel better. The coyotes challenged me once, but I stood my ground and though I hear them all around, they have not come back to my property. I know they will some day and when they do I'll go to meet them. I have a good roo too that's plenty big. That helps a lot. He's a little on the mean side, but stays clear of me and my daughter stays clear of him.
Now if I could just keep the squirrels out of my orchard I would be a happy camper.
1) critter proof coop
2) big mean roo
3) strategically placed hiding places
4) marking territory