For dry skin, opt for a light coverage, moisturizing foundation. Try CoverGirl's Tone Rehab for $9.For oily skin, opt for a more medium to full coverage, matte foundation. Try L'Oreal's Infallible Pro-Matte for $12.If you have combination skin, then you'll have to test out a few more samples to figure out which one's best for you. Read here for more tips on selecting foundations based on your skin type.