Jessica Tierney, a self-defense instructor based in Iowa and executive director of the American Women’s Self Defense Association, knows that having a few simple moves at your disposal can be lifesaving. “A client of mine who had learned self-defense used her skills to get away from a man who tried to attack her while giving her a ride home,” says Tierney. “She was able to escape and get help. I think knowing how to protect herself saved her life.”

Everyone, Tierney says, should know the basics of self-defense, which starts with paying more attention to your surroundings. “If you’re walking across a parking lot loaded down with packages, balancing a cup of coffee and talking on your cell phone, you aren’t paying attention to what’s around you. You allow a potential attacker to use the element of surprise because you’re distracted. Self-defense begins with knowing what’s happening around you so you can avoid dangerous situations.”

Related: Don’t Be a Victim: Stay Safe in Parking Lots and Garages

Knowing what to do if you’re attacked is also important. Taking a self-defense class is a great way to learn and practice techniques that can help you fend off an attack. But Tierney says learning these simple principles and moves can also help.

The principles of self-defense

“Use the hard parts of your body to attack the soft parts of your assailant’s body,” says Tierney. “The heel of your hand, your knees, elbows and feet (especially if you’re wearing shoes or boots) are good examples of naturally hard areas you can call on.”

Soft parts of your assailant’s body that are most vulnerable include the eyes, nose, throat, stomach, groin and feet. “In our classes, we tell students to aim for an attacker’s vision, wind (breathing) and limbs. You might use your thumbs to poke into their eyes, for example, or hit their nose with the heel of your palm. This can buy time for you to escape.”

Three self-defense moves to master

Tierney recommends learning these three moves:

1. The palm-heel strike. Self-defense experts say the heel of your palm can be a more effective weapon than a closed fist, especially if you don’t have experience throwing punches. “You could injure your hand if you hit someone with your fist,” Tierney explains.

To execute a palm-heel strike, raise your arm with your palm facing your target. Bend your hand back and curl your fingers in to protect them. Strike the nose or chin with an upward motion, keeping your arm straight and using your body weight. Here’s a demonstration.

2. Knee kick. Your knees can also be powerful weapons. The joint is large, hard and somewhat pointed. And it’s powered by some of your body’s strongest muscles. A knee strike to the groin is effective against both male and female attackers. You can deliver this blow at close range, if your attacker is holding onto you, by simply lifting your leg up with as much force as possible. If your attacker is pulling you toward them, use the momentum to land a painful knee strike straight into the groin. See it done here.

3. Foot stomp. Kick your opponent hard in the kneecap, then graze along the shin and stomp with all your might on the top of their foot. Doing this could break several of the foot bones, making it difficult for your attacker to pursue you.

The foot stomp can be executed from several positions. “You can do this with your heel if an attacker has grabbed you from behind,” Tierney says. You can also use the inner or outer edge of your foot to “punch” your assailant’s knee, which will allow you to land on the top of their foot with more force than if you kick with your toes. Watch a demonstration here.

Sari Harrar is an award-winning health, medicine and science journalist whose work appears in Dr. Oz The Good Life magazine, Good Housekeeping, O--Oprah Magazine, Organic Gardening and other publications.