As the warmer months inch closer, SPF becomes increasingly important to include in a daytime skin care routine. While sunscreen should be a year-round staple to protect against the sun’s harmful UV rays, the spring and summer months often come with a higher UV index. This means that UV rays are most powerful during the day, and your skin at the greatest risk of sun damage. There are some basic dos and don’ts when it comes to sunscreen and overall sun protection that everyone should keep in mind prior to layering up on SPF products.

Do use an SPF of at least 30

As we know, SPF helps defend our skin from the sun’s harmful rays. The higher the SPF, the greater your protection. SPF 30 is the minimum number you should look for in sunscreen or tinted moisturizer in order to protect your skin—this level of SPF can block approximately 96.7% of UVB rays. While it’s fine to use products that happen to include SPF, such as foundations that have SPF 15, it’s important to layer a stronger SPF underneath to ensure protection.

Do use SPF if you use retinol and/or vitamin C

If you use treatments like retinol (vitamin A) at night, or vitamin C during the day, it’s essential to add SPF into your daytime routine. Retinol and vitamin C both increase the skin’s sensitivity to the sun, otherwise known as photosensitivity. Incorporating SPF into your morning skin care line-up ensures the efficacy of your anti-aging products and protects your skin from sun damage.

Do apply at least a spoonful of SPF to your face

Experts recommend applying at least one dessert spoonful of sunscreen, and more if needed. You should be covering your eyes, ears and lips, too, as your whole face requires protection and delicate areas of the face also need some TLC. If you worry about SPF feeling heavy on your face, consider using a lightweight option to give you the necessary level of defense against harmful UV rays.

Don’t use expired SPF

Be sure to check the expiration date and shelf life of your sunscreen. Using expired SPF minimizes your sun protection, but it has the potential to be even more dangerous—it can put you at a greater risk for burns than using no sunscreen at all. It also has the ability to cause acne or other skin irritation. To prevent this from happening, keep track of when you open your SPF products and monitor the expiration date.

Don’t apply SPF just once a day

SPF should be a morning routine staple, but it shouldn’t end there—you should ideally reapply SPF every few hours to maintain optimal protection. This isn’t always ideal for makeup wearers, but there are great SPF options for reapplication that won’t mess up your full face. In this case, opt for a spray or powder SPF to set or maintain your makeup while still offering protection.