With cold and flu season kicking into high gear, there’s never been a better time to brush up on hand washing—which helps prevent the spread of germs.

The U.S. Centers for Disease Control and Prevention (CDC) recommends washing your hands frequently, and especially at the following specific times:

• Before, during, and after preparing food
• Before you eat
• Before and after you help a sick person or child
• Before and after you care for a wound or cut
• After you use the toilet or help a child use the toilet
• After changing a diaper
• After you cough, sneeze, or blow your nose
• After handling animal waste
• After handling an animal or pet food
• After handling trash or garbage

The best way to wash your hands is with soap and water, according to the CDC. If not available, an alcohol-based hand sanitizer with at least 60 percent alcohol is a good alternative—although it is not as effective as soap and water.

To wash your hands, wet them with clean, running water—warm or cold—and apply soap. Rub your hands together to make a lather and scrub them well, including the backs of your hands, between your fingers, and under your nails. Rub your hands together for at least 20 seconds—about as long as it takes to sing “Happy Birthday” twice. Rinse your hands well under running water, and dry them with a clean towel or air.