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See it in 2D

Katy Perry's two-toned shadow adds so much dimension to her eyes, and it "is a trick used more commonly than you think," says celebrity makeup artist Jake Bailey. He created Perry's sparkly lavender and lime green look for the Grammys, and he recommends using "the paler shade on the lower eye, and the darker shade on the lid."

Shadow duo to try: COVERGIRL Smoky ShadowBlast in Citrus Flair, $7.99