I have had sinus infections over the years, and a good hard dose of antibiotics was needed to really knock it, otherwise a prolonged month long misery. 

This winter, knock on wood, no colds, so far so good.

A nasal rinse is a good thing to do, Neilmed, a simple saline rinse, blow out the bad stuff, up one nostril and out the other.  It can really help.  Found at any store.  Just do it.