Migraine is diagnosed mainly from its pitta or inflammatory conditions in this case the recommendations i would offer would be a regular practice of headstand followed by shoulderstand. Both should be mild effort with a focus on developing them into a total of 5 minute practice. You may need personal instruction on how to do this. In addition one should eat a pitta diminishing diet, which can be found from any Ayurveda book.
Some migraines are also due to vata imbalance in which case they are more likely to respond to increased gentle prana promoting pranayama and meditation practices with the intention of uncovering your intuition. Such practices will definitely need an experienced instructor to give them as just any version of pranayama will not suffice. a Yoga Therapists trained in pulse reading and pranic assessment must determine the program and make sure it is changingyour pulse and balancing the vata dosha.
Yoga Therapists trained in Ayurveda are few so i am developing a course based on 2 books on the subject i have just completed. this course will be offered first time winter 2007. namaste mukunda