We wondered, is there really such a thing as mistake-proof foundation? And if so, how can we possibly know which foundation is going to be the right one for us? It turns out it's not the product alone that counts. As iVillage makeup artist Deborah Grayson outlines below, it's your skin and how you apply the product. To make your foundation mistake-proof, follow these four basic steps:

Prep your skin

"Foundation will only lie as smooth and even as the skin underneath," says Grayson, so in order for your foundation to be mistake-proof, skin must be prepped and polished to its best advantage. That means regular moisturizing, gentle exfoliating to roll off any dead skin, and even a professional facial once in a while!

Use the right shade

Foundation color must be as exact a match as is humanly possible. Not a tad lighter or darker. "For checking foundation color, daylight is best, and a slightly overcast day is ideal — that's because too much sunlight just blows out your color, and artificial light makes it impossible to gauge true color," says Grayson. So a makeup boutique with large windows is best. "If your local makeup haunt doesn't offer good light, don't be embarrassed to bring your own mirror with you to the store," she says. "Try on a few variations of color and march outside into natural light to check the color. When and only when it disappears against your skin, it's perfect," insists Grayson. Also remember:

• For beige skin, a foundation with yellow undertones will be best.
• For brown skin, peachy-orange undertones are for you.