How to Properly Apply Sunscreen Under Make-Up. It's important to keep your face protected from the sun. Many make-up items come with UVA and UVB sunscreen in them, but it's still a good idea to apply sunscreen under your foundation make-up to protect your skin from burning.
Wash your face as usual.
Dry your face thoroughly.
Apply sunscreen to your face in a thin, even coat. The average adult requires about 1/4 to 1/3 of a teaspoon to cover the face. Use at least an SPF 30, though sunscreens are available in 50 and 60.
Let the sunscreen soak into your skin.
Dab away any excess sunscreen with a tissue.
Apply your foundation as normal. Foundation with an SPF can give you added protection.