*Bring a pot of water to a boil
*Take away the pot of water from the stove
*Place a towel over your head and lean over the steam coming from the hot water
*Gradually inhale through your nose letting the towel funnel the steam towards your face
*Keep breathing the steam until your are feeling the pressure in your sinuses releasing
*Take a break from the steam by removing the towel and return to the steam once you have cooled off a bit....Within 5- 10 minutes your sinuses should be cleared and the pressure relieved

If, perhaps, that doesn't do the trick, I have one more idea:
Make a saline solution by combining one cup of warm water with 1/4 teaspoon salt.

Leaning over a sink and holding one nostril closed, inhale in a small handful of saline water into the other nostril.
Alternate this procedure with the other nostril until you feel the pressure decreasing.

The second methods sounds unpleasant, but it only feels uneasy for a few seconds. It is also a tried and true remedy for a cold with nasal congestion or a sinus infection.
There are different kinds of headaches that comprise tension headaches, migraine headaches and sinus headaches, amongst others. When I get a headache, it is usually a sinus headache-the kind that feels better when you apply pressure to your cheekbones or the area between your eyes.