How do I create a natural lip with lipstick?
For the "not looking like your wearing any" look, appraise the natural state of your lips, the color of your gums, and, with much pride, the pinkish, tawny, or brown hue of your nipples -- though I do advise the latter when you're alone!
Seriously, by following nature's paintbrush, you learn what works best for you from your own body; it's a fine tribute to your own natural beauty. Then look for tones just a touch more vivid than your natural shade.
If you're a naturally pink girl, try a subtle blue-pink.
If you're a tawny girl, try a slightly beiger, tawny pink.
If you're a brown girl, try a tone that's slightly brownish with a yellow-orange hue, like ochre.
Skip lipsticks with glossy or shimmery qualities; they'll look artificial.
Remember, you're born with the perfect hue imprinted right on you! The challenge is to honor your natural tones with just the slightest bit of enhancement. (By the way, this color theory works with blush as well.)