I find taming adult birds is easier because you can sit in the coop with them and feed them out of your hands. Eventually they come to know you are the treat person and rush towards you every time you walk into their coop. I had my silkies when they were already a week old and it had to do with a lot of me just taking a good hour to feed them all by hand while in their brooder, petting them, letting them jump into my hand, I very rarely picked them up and held them because that can be scary for babies. I acted more like a mama hen and mama hen's don't pick up their babies. I would call them over, point out food, and huddle them all under my hands like a mama hen putting her babies under her. I do the same with my chicks I have had since they were 1 day old and they are so convinced I am a mama bird that they scream when I walk away from them. That seemed to work very well for me and my juveniles still follow me around int heir coop and call up to me for food. If I sit down or kneel on the coop floor my juvies will still try to huddle under me too.
With my silkies they are tame enough I can hold them now and place them on my lap and pet them and they won't move or jump off. One of my roosters even sat on my lap for hours when I played video games and would squawk when I died in the game or jumped because of a jump scare. He would stay in my lap but he would bawk excitedly thinking something was obviously coming to eat us. My other silkie rooster Yuki will still jump to my shoulder to perch on my shoulder while I walk around and do barn chores. I call him the baby dragon because of how his toes curl over my shoulder like claws and his chest hands over like he's a puffed out proud baby dragon. Chickens are super food driven though so as long as they get use to you being a treat and food bringer they will love you.
