I wrote a whole page about Sinus infections and home remedies. I realize you probably don't have an infection but some of the tips can help drainage. You can find the page if you look for the button "Home Remedies" then scroll to the middle of the page and look for "Home Remedies for Sinus Infection".
I'm a real believer in the Neti-pot. It's amazing what a little sea salt can do for sinus problems. If you don't have a neti-pot you can make some nose drops if you use about 1/2 teaspoon of sea salt and about a cup of warm water and stir until the salt disolves and just put a couple of drops in each nostral a couple of times a day.
