Things like movie theatres, cluds & crowded venues & glare from the sun are common environments that may cause migraines.
Magnesium deficiency has been shown to contribute to the onset of migraines, so taking a daily supplement may help reduce outbursts.
Dry air can increase chances of a migraine. Open windows & doors, and use a humidifier or ionizer to decrease air dryness.
Hot water is an excellent aid for softening the grips that clenched can bind themselves.