I've most often fed by hand, and only a few times used millet to persuade them. This works from my tamest tiel down to my wildest who has no interest in humans and tends to be very flighty if I get too close to him. I'll include a few photos with a short history.
Sunshine came with her family (parents and brother) and was probably hand raised but not handled much in who knows how many years, so she had some interest in humans but not enough to really want to hang out with me. I was able to get 5, non-tamed, flighted budgies, all adults, to eat from my hands, so I assume this is how the behavior from her started. Sunshine had landed on me one morning when I was refilling the food bowls, but she landed on my back, so I couldn't see who it was, and had assumed it was Casey, my tiel, even though weight seemed off. She took off a second later, and that's when I turned my head and realized it wasn't Casey.
It took a couple of weeks of Sunshine following me around and landing on me a second time before it finally "clicked". I offered her food by hand, which took time for her to get accustomed to coming to me, but she got there! First vid shows after she became comfortable with this behavior.
[ame=http://www.youtube.com/watch?v=q88bN30qOjo]Sunshine in the Morning - YouTube[/ame]
Next couple of vids show Faye. She had had at least 3 homes prior to mine and I'm sure she wasn't handled in the last two. She used to have a mate, but he died in the previous home (wont even get into that story). I don't know if she was hand raised or parent raised, but she's a sweet tiel, personality wise. She saw me feeding Sunshine (prior to finding her another home), and wanted to join in. First video shows you how unsure she is, and she is by no means being forced to eat from my hand! There's food in the dishes behind her.
[ame=http://www.youtube.com/watch?v=R9w9w8nMRmw]Hesitant Faye - YouTube[/ame]
Same tiel, different food! First video, I had seeds. This video, I have pellets (Faye has always been good about eating pellets, even though she came to me on a seed only diet). You can see just how much more confident she is in herself and how comfortable she has gotten with me.
[ame=http://www.youtube.com/watch?v=rH9ZWxhCSAE]Not So Hesitant Faye - YouTube[/ame]
And this last video shows Tomi Girl - tame-ish, Pistachio (wild tiel, plucked head), then Casey, tame girl.
[ame=http://www.youtube.com/watch?v=XjKmHswgiHs]Cockatiel Feeding - April 24th - YouTube[/ame]