Take a look at some of the Stickies in the Taming and Bonding portion of the forum, there is lots of good information there. None of my birds are really tame but all of them will step up onto a perch and most of the time I have to nudge their belly to get them to do so. Unless you have to catch the bird in a hurry I would not throw a towel over the bird, that would be very traumatic for the bird and I think counterproductive. Positive reinforcement is the best way to train, you are rewarding the bird for a action that you have asked for. You have to look at things from the birds point of view. Regarding your hand, it depends on what you mean by reacts badly. If you mean biting, if you withdraw your hand you are conditioning the bird to bite under certain conditions as the bird will associate its biting with getting you to remove your hand. Most birds do not like to be petted or held so I would suggest you do not try, the bird will associate you with an action it does not like . You have to gain the birds trust, you can work with your bird daily but keep the training sessions short, 10 minutes or so.