Whether you’re indoors or outdoors, sunscreen is a skincare staple that should be used every single day for preventing skin conditions like hyperpigmentation and skin cancer.

According to Dr. Sam Bunting, a London-based cosmetic dermatologist, the most effective way to apply the correct amount of sunscreen to your face is by using her 13-dot technique.

To apply sunscreen this way, squeeze some product onto the back of your hand and place three dots across the forehead and three down the sides of the face, from cheekbone to cheek.

Then, place a dot of sunscreen on both sides of your nose and two dots on your chin. Take whatever is left on your hands and rub it onto your face.

Even after using this application technique, it is still important to frequently touch up your sunscreen during the day, which includes reapplying SPF over your makeup.