Drink lots of water. Headaches are often caused sa pamamagitan ng lack of moisture in the brain. Or something like that. (derp-level biology)
Lay down for a while. You'd be amazed how much a little rest can help. Opening up a couple of windows helps a great deal to.
But in the end, unless you're allergic or something like that, I would payo you to take an asperin. The effects of asperin kicks in after about 30 minutes. Always works for me. On a segundo thought, take in the aspirin right away, and perform the above things I mentioned. That oughta be the best way to get rid of a headache.
Don't worry, medicine isn't that bad. Unless you have an allergy.