How to do it: Dissolve a quarter teaspoon of salt in a half cup of warm water, and fill a nasal-spray bottle with the solution. Spritz twice into each nostril, then have your child blow his nose into a tissue. (If your child is too young to blow, use a bulb syringe to suction out the fluid.)
Why it works: Salt water loosens thick mucus, making it easier to discharge from the nose, and restores the natural moisture of the inner membranes.
When to call the doctor: If you think your child may have an ear or sinus infection. (Symptoms include a fever, persistent cough, earache, or yellow or green nasal secretions.)