It’s time to share the best ways to prevent a cold or the flu this winter:

First: Keep your hands clean! It may sound simple but infectious diseases experts say it’s the single best way to keep from getting sick. So, wash up every time you push an elevator button, grab a doorknob, or fill your gas tank. The average woman washes her hands about 5 times a day. Doing that’ll cut your risk of viral infections in half. Increase that hand washing to seven times a day, and you’ll cut your risk of the flu a full 75 percent.

Another way to stay healthy this winter: Hang out with your friends. Friendships can counteract the harmful effects of stress hormones which can weaken your immune system, leaving you vulnerable to viruses. And new research shows that the more friends you have, the healthier you’ll be. In fact, when college students were given a flu vaccine, those with the biggest social networks produced more flu-fighting antibodies.

Also: Keep your family’s toothbrushes separated! Experts say that storing everyone’s toothbrush in the same glass guarantees cross-contamination. Instead, use a toothbrush holder that keeps them from touching.  And when you’re done brushing, shake the excess water out, so it’ll dry faster because germs don’t live as long on dry surfaces.

One final way to avoid colds and flu this winter: Practice tai chi. Studies show that tai chi can boost your body’s cold-fighting defenses by as much as 47 percent and can make your flu shot 300 percent more effective. Why? Scientists say that the slow movements and controlled breathing in tai chi lowers blood pressure.  It’s also a proven mood-booster, and improves the quality of sleep, both of which increase your immunity.