When some of us fall ill, we begin to wonder what brought on the coughing, sneezing, and aching. We might blame a sniffling person in the checkout lane or an office pandemic.

Obviously, there are many ways to catch a viral or bacterial infection. But the single best way to minimize that risk is to wash your hands. And while that might seem simple—it is, after all, a skill taught to us as children—you may not be doing it correctly.

Popular Science recently highlighted the importance of handwashing, noting that people may touch their face up to 52 times per day. If they’ve just touched a surface that’s harboring germs, that’s 52 opportunities for pathogens to settle in the mucus membranes and lash out with everything from flu to respiratory infections. Proper hand hygiene, according to the Centers for Disease Control, can reduce the community risk for respiratory illness by 16 to 21 percent and for unpleasantness like diarrhea by up to 40 percent.

The problem? People tend to wash too quickly, sticking their hands under the faucet for a few fleeting moments and moving on. In 2018, the U.S. Department of Agriculture evaluated 383 subjects and found that most did only a cursory wash.

It’s better to follow the CDC’s advice, which is to get your hands thoroughly wet with very warm water—which can be enough to kill some microbes—and then lather up, making sure to reach every fold and surface area between your fingers, around your wrists, and under your nails.

So far, this is not the stuff of surgical scrubbing. But here’s where most people drop the ball: Rather than soap up for just a few seconds, try to keep the cleaning going for 20 seconds. That’s two cycles of the “Happy Birthday” song. When you’re done, dry with a clean towel.

It’s good to wash up before eating, after coming from outside, handling an animal, or prior to touching your face for any reason, like putting in contacts or flossing. Obviously, washing after using the bathroom is a must, but you knew that.

As for hand sanitizer: It’s good for when there’s no running water available, but it can’t kill all germs, and it won’t do a whole lot if there’s visible dirt or grime on your hands. Water and soap remain the gold standard.

[h/t Popular Science]