Dual cast any projectile spell, such as Firebolt, at Dragon skeletons to get them out of your way. Crouch first, to aim "up", so that the dragon flies upward, and that will help the skeleton clear any buildings or other obstacles in the way. Sometimes the skeleton will fly so far away, you won't be able to see it anymore! I do this with dragons that die just outside the gates of Whiterun (The gate that brings you into the city, not the outside gate) because it is annoying as hell to have NPCs constantly stand in awe of it. It's also funny as hell to blast those things!