Blend in the concealer with a flat, firm brush like Real Techniques Oval Brush, $13. Katie prefers using a flat brush because you get the same pressure as a fingertip when applying, but less of a mess.

Gently tap over your concealer application with your fingertip to remove any excess and make it look more like real skin.

Now, apply your regular concealer (the one you typically use to cover redness or blemishes on other parts of your face) over the area. Katie's current favorites are Urban Decay Weightless Concealer, $28 and NARS Creamy Concealer, $29.

Using your brush again, blend your second concealer well. Blend it downwards (covering more than just the dark circles) to add brightness wherever your face needs it.

Again, use your fingers to blend over all of the concealer that you applied to remove any excess that your skin simply doesn't need. If you're worried about the concealer settling into any wrinkles, Katie says this is the crucial step to remember to make sure that excess makeup doesn't hang around.