Actually, I did this whenever i needed to hold him for something;releasing only when he'd calm after I'm done,along with a treat; but I have a different method I've been using lately.
I've been trying to give him head rubs and pets,but he doesnt like it,thought he rubs his head on me if I've been holding him for a while.
So,to get him used to my extended fingers and hands above his head,I've been doing this at random:
Touch closest wing, next his wing,his back or his tail,;one of the previous spots I havent touched yet, then either his beak, chest or head, then the rest of the spot i didnt touch.
I did this cause I've been kinda kissing his back sometimes,and recently I found I can nuzzle his back,or neck and even his head with the tip of my nose without protest, and once he even returned the nuzzle by grabbing my nose with his foot and rubbing his head against my nose when I held him to my face.
The progress isnt so good,as he's now rubbing his head on my fingers,and nails especially which ever nail he sees as the longest; 'even used my fingerprints against his cere ,but he's still skittish when I'm trying to start petting him. Because of this, whenever I need to hold him,I've been giving him a quick double pat/pet on his head, when he's calm, before letting go,and hes allowed that more so that not and remained calm before being released.(It depends on why I needed to hold him to begin with)