If you have small eyes like Renee Zellweger:
How to use it: Line your eyes with a pale liner, dust a light eyeshadow (or even a bright concealer) over your lids and apply a shimmery highlighter right under your brow, Stern says.
What NOT to do: Scrimp on your lashes. You know what a padded bra does for your boobs? Well, lash primer does the same thing for your lashes. Thomas recommends using a lash primer first for an extra boost, and then adding two coats of mascara.