Park yourself in front of a mirror and take a good long look at your gorgeous self. Whether you are porcelain fair, cocoa dark or somewhere in between, your complexion has either warm or cool undertones. Not sure where your skin falls? Check out the veins at the inside of your wrist. In warm-skinned girls, the veins often have a greenish cast -- if that's you, you'll glow in earthy shades of gold, green, brown and peach. Cool-skinned girls usually have bluish veins -- and are knockouts in pinks, purples, grays and true reds.
Consider your skin coloring. If you're fair enough to make Snow White jealous, stick with sheerer shades to avoid washing out your face. If your coloring is rich and dark, look for deep, intense shades. They may look crazy in the package, but they'll stand out nicely on your skin. If you have medium coloring, you have a little more leeway.
Grin and bare it: Wash off all your makeup -- yes, really, all of it -- before you head to the makeup counter. So you've never faced the public with a naked mug before? Congrats -- there's a first time for everything. Yeah, it might feel strange, but working with a fresh slate is key. When you find the right color, it shouldn't need help from any other makeup to make you look great.
Hit up the department store and get to know your friendly neighborhood makeup counter ladies a little better. Try on different shades of makeup here, and don't be afraid to test drive a new color you wouldn't normally consider. And, yes, department store makeup is pricey, so don't feel that you have to drop dough here. You can always get an idea of what shades work for you and then shop for similar hues at the drugstore.
Score some samples. Most major department stores are generous with makeup freebies if you ask the cosmetic counter ladies nicely. Department store lighting doesn't really do wonders for anybody's complexion, so check out what each shade looks like in natural lighting before you make the final decision.
Pretty much every gal has one complexion in the summer months and another in the winter. Work on building a cosmetics wardrobe for each season. At the very least, you should have two foundations -- one darker shade and one lighter shade. You can even blend the two together when necessary to customize your own perfect hue.