Caribbean Sea shades look so summery. Apply Rimmel ScandalEyes Waterproof Kohl Kajal eyeliner in Turquoise ($5; at mass retailers) or Chanel Stylo Yeux Waterproof Longlasting eyeliner in Jade ($30; chanel.com) to the outer half of top and bottom lids.
Smudge into lashes with a cotton swab for a watercolor effect.