It’s recommended you wash your hands for about 15 to 20 seconds, or roughly the same amount of time it takes to sing your ABCs. (For Health Beat)

Hosting a holiday party is a sure way to lure in family and friends, but it’ll sometimes bring in uninvited guests: germs.

Amid your festive gatherings this season, it’s important to keep good hygiene top of mind.

Proper hand hygiene is the single most important thing you can do to help keep you and your loved ones from getting sick, Mallory Davis, PhD, lead infection prevention specialist at Corewell Health, said.

“Germs and bacteria are spread via our hands because they touch everything,” Dr. Davis said. “The only way to get the germs off your hands is to wash them.”

You should wash your hands before you eat and after you use the bathroom. You should wash before you cook and after you’ve touched raw meat or eggs. You should also wash your hands after you blow your nose or sneeze, and before you touch your face.

“If I’m just sitting here working, I won’t wash my hands that often,” Dr. Davis said. “But if I blow my nose or take a bathroom break, I always wash my hands.”

Surfaces and objects that we might not necessarily think of as being covered in germs—TV remotes or doorknobs, for example—may actually have more germs than a toilet, Dr. Davis said.

Any items that people handle regularly—a shopping cart, gas station pump, ATM keypad, elevator buttons—can harbor germs.

Cell phones are especially problematic.

“Think about it,” Dr. Davis said. “Everyone takes their phones into the bathroom and you pass your phone around to show pictures to others all the time. A cell phone collects all the germs from any dirty surface you might touch.”

So if you’ve touched a lot of objects or surfaces, it’s a good idea to wash your hands. It’s also recommended you safely clean your cell phone about once a day.

Soap sense

A smart tactic to promote frequent hand-washing: Find a soap that has a favorable smell.

“This will lead you to use the soap more and encourage you to wash your hands more regularly,” Dr. Davis said. “And the same goes for hand sanitizer—find one with a scent you enjoy.”

Also, you don’t need to be choosy about the type of soap.

“Any soap works well with water,” Dr. Davis said. “It doesn’t matter as long as you are using soap.”

Time and technique

It’s also important to wash thoroughly.

“We always say focus on the palms of your hands, backs of your hands and in between your fingers, your thumbs and your fingertips,” she said.

Aim for about 15 to 20 seconds of washing. A good trick is to sing “Happy Birthday” twice, or say the ABCs in your head—that’s roughly the same duration.

Set the right water temperature, too.

“The temperature of the water needs to be comfortable so you will do it for 20 seconds,” she said. “If it’s too hot or too cold, it may impact the amount of time you spend washing your hands.”

Got sanitizer?

In general, hand sanitizers and hand-washing are both acceptable methods of killing germs.

But if your hands are visibly soiled, opt for soap and water. Hand-washing ensures a physical removal of bacteria as you scrub with the soap and water, Dr. Davis said.

Hand sanitizer kills germs on contact, but if you use hand sanitizer frequently it’s also a good idea to carry along some moisturizer.

“There is a risk of dry or cracked skin on your hands if you are using hand sanitizer too often,” Dr. Davis said. “Moisturize after you sanitize and moisturize after you wash to keep your skin healthy.”