I have found using the Watson Headache ® Approach, developed by Dr Dean Watson from Australia, invaluable in treatment of headache and migraine.
Treatment is based upon assessing whether your upper neck is involved (you do not have to suffer from neck pain for this to be the case). An upper neck restriction can sensitise you to being more susceptible to triggers. Restoring normal movement with Watson techniques can have provide an effective and long term solution; frequency, intensity and duration of symptoms can reduce substantially or be resolved completely.