My amazon and both my greys were clipped as well. They never had the chance to learn to fly from day one.
But my 10 year old son at the time, taught my amazon to fly. He would hold her as she was perched on his hand, and he would gently run towards the couch, a out 5 feet and say, "fly", she loved this. After a while, she would extend her wings out, then eventually after much practice, she would try to fly and she had the soft couch to land on. Then he would get all excited and praise her. She loved it! She became more and more confident and would try it on her own after some time. Now she flys all over the house yelling her little heart out!