Simple yet defining, lining the corners of your eyes gives them definition and shape without looking like you’re wearing tons of makeup. This is the same sort of effect as highly contrasted shadows.
Just use a felt-tipped liner pen, like Eyeko’s Eye Do Liner, and draw a small line in your inner corner, following the line of your top lid. Then line your outer lids in a sideways v-shape. Putting these “brackets” around your eye gives the illusion that they appear bigger in a mysterious way. You may not want dark circles under your eyes of course, but a little shadow manipulation can work in your favor here.