I hand-feed grasshoppers I catch around the yard. I also let them peck at hen scratch in the palm of my hand. I feed tomatoes out of my hand.
Now when I want them to go into their tractor, I yell, "Bo-Bo!!", stand in front of the door, and bend over as if I have something in my hand. They run so fast they barely stop as they cross the threshold, and I normally throw in about a cup of hen scratch just ahead of them, in case one decides she knows the gate is about to close! My dad just shakes his head at this whole thing; he says, "You're supposed to call them with, "here, chick chick chick"". BOBO just doesn't work for him! LOL!
As for my 3 "tester chickens" (game hens who were wild and probably abused), two of them are just now getting to understand what being called and fed is all about. They are still very difficult to get back into their coop, and still prefer to roost in the trees, even after months in their tractor.