I would help out in the pet shop for the longest time, and the budgies were very scared and not hand-tamed. They would run to the other side of the cage whenever and human came by (they were clipped) and parents would let their kids grab them roughly. I decided to try to hand tame them, and developed a "formula".
Day one: take some millet, and sprinkle the chunks (not on the stick) onto the cage, chill there, and leave. Do not attempt to grab them.
Day three: Wait by their cage so they're used to you, and repeat the process.
Day four: Same as day three.
Day five: Wait by their cage for a minute,with your hand in it. Once they relax, put some millet in your hand and wait for them to eat it. Keep it in your hand, and make no sudden movements.
Day six: Same as day five, but get farther from them.
Day seven: Start teaching them to step up. Make sure no one comes up and scares them, or you may have to start over.
Hope this helps!