Step 1: Apply foundation to your entire lip, says Napoleon
Perdis. Not only does this help remove the natural pigments of your lips
for truer lipstick colors, but it can also help you realize where your
liplines actually are.
Step 2: Using a white eyeliner pencil, very softly feather the
pencil over the natural contour of the lip. Or use the pencil to make
lips fuller or thinner by drawing it past your natural lipline or within
it.
Step 3: Redo the line with a lip pencil in the color of your lipstick.
Step 4: Apply lipstick with a lip brush in a downward motion. So,
from your cupid’s bow to each outer corner, then from your outer corner
to the center of your lower lip. This ensures an even application of
the product, says Hawker.
Step 5: Apply a light shade of base foundation around the new lip line, blending to a soft edge with a lip brush.
Remember, light colors reflect light, so using lighter lip colors will
give a fuller appearance. Dark colors absorb light, so they will make
lips look smaller/thinner. Finally, try this popular trick used on
Victoria’s Secret Angels to give the illusion of a fuller pout: Apply a
dab of gloss to the top part of your Cupid’s bow and to the center of
the bottom of your lip.
source Total Beauty.com