What is a good stretch for your neck, especially when I have a migraine?

Diana Z.
Lie on your back, take a soft roller and place it under your head, at the hairline. Move your head back and forth slowly, maybe try a supine figure eight. Stop on the occipital bump on each side and hold for a few breaths. Move the roller further up the back of the head and begin moving your head straight up then down towards the chest repeatedly. With the head up, tilt it a bit to the side and reach the opposite hand down towards the foot. Repeat a few times, then do the other side.
Your neck will thank you!
Anton P.
Shoulder rolls are great for headaches! Roll your shoulders forward a few times and then roll back. Repeat a few times.

Another exercise is to tuck your chin into your chest, lace your fingers behind your head, and slowly rock your head side to side.

Emily Y.
I was going to try to post a picture of my favorite stretch but it wont let me so I'll try to explain it :). Stand up straight, reach your left hand over and place it on your head right behind your right ear, pull straight down and hold. Twist your head slightly if that feels good. Do as many reps as you'd like and repeat with the opposite side. Hope this helps!