First make sure it is sinusitis because other problems like asthma, upper respiration tract infection, tooth problems may appear like sinusitis.
If you have any of the above symptoms consult your doctor for proper treatment.
Steam inhalations is of a greater advantage then any other medicine.
Avoid cold food & cold drinks.
Avoid foods which have preservatives & are artificially coloured & flavoured.
Avoid smoking and avoid other environmental pollution if possible.
Avoid swimming at unknown places where chances of contamination are more.
Avoid air travel during upper respiration infection.
Use warm compresses on you nose to help open the sinuses.
Do warm water gurgles.
Drink plenty of fluids.
People with diabetes are prone to sinusitis so keep diabetes under control with proper treatment.
Avoid contact with people who have cold or at least don't share their towels, silverware & beverages.
Always use a handkerchief when sneezing.
Wash your hands frequently as cold viruses often survive for hours in the open such as doorknobs, money & other surfaces.
Regular moderate exercise helps to strengthen your immune system thus prevent colds & other infection.
A healthy diet full of fruits, raw green vegetables help to stimulate secretions & break up sinusitis.