Do the foot drills.
Try to find a chiro who does extremity adjusting. If you do this, give it up to 3 adjustments, if that doesn't get it then move on.
Vibrams or barefoot a lot, walking on uneven ground.
Numbers 2 and 3 in this article: http://www.t-nation.com/free_online_...obility_drills
Consider getting a session with a Z-Health trainer to properly learn the medial/lateral tilts and toe pulls.
I've heard good things about the JumpStretch routines with bands for combined ankle strength & mobility.
That's a heck of a start. I had a bad history of spraining ankles when I used to hoop. I don't have any issues with my ankles anymore.