dodging his homing iceball. the trick is to at the near last second angle your flying sparrow towards the direction of the iceball at a 45 degree angle, its easier to practice this when you are far away from him but becomes harder to do when you're up close beating on him
when he makes his giant ice wall down the middle, charge up a blind arrow when he explodes it near the center of the map, blind arrow has a decent range and he normally lands close to the center after breaking the ice wall.
also dragons tend to shift their movement twice so be careful about instantly moving when they move, you might fall into place with his ice breath
that's all I have, hope it helps