Write an article based on this summary:

Find colors that match your skin tone. Check your undertone Test the color under natural light. Choose between powder and liquid foundation. Consider the finish.
Foundation should be as close to your natural skin tone as possible. When picking out samples to test, go for the one that seems to match best, plus the options one shade darker and one shade lighter. Most makeup lines have a numbering system in place to help guide your choice, but each system only applies to that particular line. Most brands go with numbers from 10 to 50 or 1 to 10, with the higher numbers for darker skin. . Most foundation is targeted at a particular undertone, summarized as "C" for cool, "N" for neutral, or "W" for warm. Some makeup companies even mix tones for an even closer match to your skin, so you might also notice letter combinations like "NC" or "NW." Picking the wrong foundation could leave you with an ashy or coppery appearance. This is especially important for people with dark skin color, but everyone can benefit from this test: Examine your skin without makeup on, under daylight or neutral white light. Hold a piece of yellow fabric or gold jewelry under your chin. If this gives your face a healthy glow, you have warm undertones. Hold a piece of red fabric or silver jewelry under your chin. If this complements your face well, you have cool undertones (which can range from red to blue). If it's hard to tell, you likely have a neutral tone, or you may need different foundation for different areas of your face. Or for a quick but unreliable test, check the veins on your inner wrist. Blue means cool undertones, green means warm, and bluish-green means neutral. Unless you spend your day under bright department store lights, what you see in the store won't be what you get. Head outside with a mirror while you have the samples on your skin. The sample that blends in to your skin tone almost invisibly is the perfect choice of foundation. Give the foundation a few minutes to dry and oxidize before you judge it. After it has dried, check to see how it looks. If you plan to apply bronzer and blush, your face will end up a bit darker than the foundation. In this case, it's sometimes preferable to go one-half to one shade lighter with your foundation. If nothing is quite right, mix two foundations together on your skin. Both sides have strong adherents and strong detractors. Some things you may want to keep in mind when deciding which type o foundation is right for you include: Liquid foundation provides more control during blending. However, poor blending or an imperfect tone match can leave obvious lines where the foundation ends. If your skin is oily, choose an oil-free or non-comedogenic example. Powder foundation (especially mineral powder) absorbs oil and sweat, but can settle into a caked-on appearance, even adding definition to wrinkles and scaly skin. Use a light touch to minimize this effect. You can wear both at the same time. Applying a liquid foundation first and then applying a light layer of powder foundation can also help to set your makeup and make it last longer. You've spent all this time choosing a foundation, but you have one final decision to make. The finish is a matter of personal preference, guided by a few principles: Most foundations are semi matte (even if not labeled as any particular finish). These work well on almost all skin types. Matte foundations work well for toning down oily skin. Illuminating foundation increases shine and can help to diffuse wrinkles.