As promised, here's another crystal grid layout for you! I call this one "The Halo" for pretty obvious reasons. :) I have illustrated it with round circles to represent your gemstones. If you have pointy crystals to use, those would be just fine. Remember to lay the crystals so that the points face outward, though! Otherwise, your standard polished/tumbled crystal gemstones will work perfectly here.
I would always recommend using three amethysts for headaches and migraines; not only has it been typically carried and used for such ailments for thousands of years, the color purple also corresponds to the crown chakra which is just where we want to concentrate on when pain occurs in the head. You can also use indigo stones like lapis if you would prefer to do so. (Use what you like -- I happen to like amethyst!) Place two just above the sides of your head, and add one to your forehead.
You'll need two orange stones as well. I also recommend using orange or brown agate, or perhaps tourmaline to represent the sacral chakra, which is a great source of fortification for pain management. Place them just above your eyebrows. Agate is well known for its healing properties, and pain soothing attributes. I'd try to find some agate first, but tourmalines are also wonderful healing stones.
Thirdly, turquoise stones are required -- you will need two of them. They should go directly underneath the amethysts which are laid around your head. Turquoise is great for its uplifting and positive energy, as well as its protective properties.