For future reference, what a few of the other members said is exactly what you should do! Don't use a towel! But *DO* allow them to come to you, with some encouragement!
I once had five adult, flighted budgies that were not tame. As an experiment, I wanted to see if I could get the budgies accustomed to me enough that they'd come to me without being terrified. I started this by feeding them every single morning by hand just inside the cage door. Once all the food was gone, I'd refill their food dishes for the day and repeat the next day.
[ame="https://www.youtube.com/watch?v=fUx81WHTUwk"]1 Bird in hand Leads to Many - YouTube[/ame]
After a couple of weeks of that, I had started to feed them with my hand on the outside of the cage door but still near it. If they wanted to eat from my hand, they had to climb out! I repeated this for a couple of weeks, then I tried about four feet away from the cage. You can clearly see how well it worked out!
[ame="https://www.youtube.com/watch?v=AlSm4uFZzVU"]More Budgies!!!! - YouTube[/ame]
I also had a small flock of cockatiels (5 cockatiels, 1 tame, 2 not afraid of me, 1 kind of scared of me and 1 absolutely freakin terrified of me!). Well, one of the tiels (previously hand raised but not handled in a while) started following me around the room. She even landed on me twice, a behavior she had never done before. I was extremely baffled by this new behavior, until I realized what she wanted. She wanted me to feed her by hand! I had no intentions of feeding the tiels by hand but I figured why not? Sunshine was quite happy that I was finally "paying" attention to her and giving her what she wanted. At first she was very shy and hesitant. She kept looking up for danger, prepared to fly at a moments notice. Still, she demanding this kind of interaction between us, so I kept it up. Sure enough, over time, her confidence grew and her skittishness disappeared to the point that she was then flying to my hand to be fed.
[ame="https://www.youtube.com/watch?v=q88bN30qOjo"]Sunshine in the Morning - YouTube[/ame]
After doing this behavior with Sunshine for maybe a couple of months or so, I was given another cockatiel. Sure enough, Faye was watching Sunshine! And next thing I knew, I had two birds begging to be fed! Only, Sunshine was confident in this behavior and Faye was scared! She was more so on the alert than Sunshine ever was, and far more hesitant about eating from my hand, but she still wanted to. You can tell by her behavior in the video. If you think I was starving them, well right behind Faye was dishes of food that the other tiels were eating out of! She didn't *HAVE* to eat from my hands, but she *CHOSE* to.
[ame="https://www.youtube.com/watch?v=R9w9w8nMRmw"]Hesitant Faye - YouTube[/ame]
So I continued feeding Faye by hand in the mornings. Faye came to enjoy this interaction between us so much that if I didn't feed her by hand she would demand it by following me around the room until I fed her! In fact, she didn't care what I fed her, as long as she was willing to eat it! This next video she's eating pellets! (I never had to convert her to eating healthier, she simply did on her own!) You can also tell that her behavior is completely different! She's not on alert and quite confident!
[ame="https://www.youtube.com/watch?v=rH9ZWxhCSAE"]Not So Hesitant Faye - YouTube[/ame]
Although I had had no plans to feed all the tiels by hand, I decided to give it a go? Why not? I had one very extremely skittish cockatiel that would fly off the moment I got too close to him. There was no way he'd come to me and no way I could get close to him without him freaking out. So I started feeding the rest of the tiel flock by hand. And something amazing happened!
Pistachio was on high alert. If I moved even the slightest bit the wrong way, off he'd go! He'd walk over, take a bite or two, then move away. Sometimes he'd walk over, peck my hands, then walk away. Eventually he started eating from my hands. He wouldn't touch my hands, but he'd eat from them. Touching was a big "NO NO"! If he found himself accidentally touching me, he'd freak out! (heck, he wasn't the only one! LOL I got scolded for their mistakes!) But soon, Pistachio started touching my hands with his toes and he didn't instantly burn up, nor did I chomp his head off! Then it was ok to put a foot on my hand. Again, no instant death or anything but still kind of scary! And one day he got the courage to get up with both feet! Sure, it took some encouragement, but he did it! And once he got comfortable eating from my hand, I was able to get him to fly to my hand to eat rather than having him step up.
The amazing part however occurred first while he was on the ground looking for scraps that had fallen and when he didn't find much, he flew from the ground to my hand. By about that time I had ran out of food, so I *VERY SLOWLY* walked over to the food containers with him on my hand, not budging. I slowly got some more food for him and allowed him to eat. Wait.... what?!?!?! He flew to my hand when all it had was seed hulls in it and waited patiently for me to get more?!?!?? OMG!!!!!!! And then it happened again, another time, except he flew to my shoulder and waited for me to get food for him when I had none. I never expected that of him, especially since he is an older bird at least in his teens, but here he was, doing it!
I have a video of Casey (tame cockatiel), Tomi Girl (kind of tame) and Pistachio (plucked head, skittish bird) eating from my hand.
[ame="https://www.youtube.com/watch?v=XjKmHswgiHs"]Cockatiel Feeding - April 24th - YouTube[/ame]
I think the most amazing thing is is that I was only interacting with them for 5-15 minutes a day, max 20 minutes? And it was a once a day thing, yet had spectacular results! In fact, the birds far exceeded my expectations! And it wasn't difficult or frustrating to do! I didn't have to use a towel. I didn't have to force the birds to do something they didn't want to. I gave them the choice to CHOOSE.
Oh, and since the cockatiels? I was given a hands off red throated conure that would bite the bloody snot out of anyone who got close enough to her! Unless of course you were giving her scritches and she was in a good mood, you wouldn't get the bloody snot bitten out of you for maybe a moment or two longer?

I didn't use the same technique with her as I did the budgies and tiels, but she's pretty demanding, too! And she loves strangers! Still bites (I haven't had her for very long) but I no longer have blood to donate! She's pretty amazing, even though she didn't come to me tame!