These tips are from Dr. Vinay Goyal who has a bunch of dignified letters after his name.
1. Frequent hand washing.
2. Hands off the Face approach. Resist all temptations to touch any part of the face.
3. Gargle twice a day with warm salt water (or Listerine).
4. Clean nose once every other day with warm salt water. Either use a netti pot or blowing nose hard and swabbing with Q tips soaked in warm salt water.
5. Eat natural foods with Vitamin C. If taking a supplement, be sure to also take Zinc to boost absorption.
6. Drink as much of warm liquids (tea, coffee, soup) as you can all day.
Viruses can only get into the body by the portals of the nose and mouth. It's not as much a problem coming into contact, but the proliferation. These 6 steps help avoid the proliferation by ridding the body of the germs at the start. They are cheap and easy ways to help keep your family healthy, or at least give you a boost in the odds.
(Thanks mom for the list)