I also spent my entire life plagued by various kinds of headaches. The trick is to figure out what your triggers are. Whenever your head hurts, recall what you've eaten, how well you've slept, how stressed you are, whether you're dehydrated or not, and what your posture has been like. Once I eliminated the headaches I got from consuming foods I'm allergic to (primarily caffeine), I found that my head still hurt quite often. And then I realized that most of my headaches were tension headaches. And I've learned how to manage them! Here's how:

Tension headaches arise from simple muscle tension somewhere in our backs, shoulders, necks, jaw, or head muscles. People often get tension headaches when they're stressed because they're hunching their shoulders, clenching their jaw subconsciously, etc. And I've found that I get tension headaches from, in addition to stress, poor posture. So find out where your greatest pain is coming from. And then stretch it out. You can get someone to massage you, or massage yourself, or, as I said, do stretches. Find out what works for you! Whenever I start getting pangs now, or on days when I now I'm stressed, I just make sure to periodically relax and stretch my aching muscles. The stress from whatever spot is hurting us--whether in our jaws or our backs--extends up to the muscles around our heads, which is what exerts pressure on our skulls and makes them hurt. So if you relax those, the rest will follow.

That said, a good way to test if your headache is a tension headache is to rub your forehead for a minute (Even a second or two will do) and if it relieves some of your pain, then you know you have a muscle problem somewhere. The trick is only to figure out where and how to mitigate it.

Other things I get headaches from: bright lights, loud sounds, (both give me migraines), strained vision, sleep deprivation. I've also heard its possible to get headaches from high blood pressure.

Hope that helps!

Depends upon what the source of the headache is... I used to have debilitating headaches that the neurologist could not solve. Eventually I stumbled upon the solution as mine were due to dehydration. When I started training for a marathon with a group the emphasis on water caused me to increase my hydration. Bingo, problem solved. I still get horrid headaches when I get dehydrated but it is easy to solve that problem. So, there is one easy thing to try.

Now for tension and eyestrain headaches, I will leave those to someone else to offer up suggestions.

I did forget to state the obvious that some others have added, go paleo if you are not already there.

I haven't had a single headache since going paleo (roughly 7 months now) - after years of regular (at least weekly) headaches.

How clean is your diet?

Too much protein and not enough fat can sometimes be a problem. YOu didn't say if the headaches have always been there or if it's a recent thing. Also, caffeine can cause headaches, either too much or not enough if you are addicted and not meeting the needs of the addiction.

Mine were always cued by either... ...drinking more water or... ...juming around (hurts but gets the blood flowing which eventually eases the pain).

What always made it worse: Lying down.

Headaches are often a sign of gluten triggers/inflammation and magnesium deficiency. Mag alone reduces the intensity and frequency of migraines/headaches by 50% compared to placebo in some clinical trials. Mag relaxes the endothelium of blood vessels.