Lashline definition

From lashline to brow, apply the lightest color.

From your lashline to your crease, put on the next-to-lightest color.

On the outer corner (partially in your crease, partially on your top lashline, in a "vee" shape), you'll apply the darkest shade.

If using two colors, do a wash from lashline to brow, plus a deeper color in the crease.