Foundation is a great tool to even out discoloration, help conceal minor skin flaws and give you a great base upon which to apply the rest of your makeup.
The most important factor in choosing a foundation is finding one that matches your skin color exactly. Buying a different shade to alter or improve your skin coloring only gives you an unflattering, unnatural appearance.
Foundation products are available in many forms and in many price ranges to suite your needs and budget. Drug store brands offer great prices, but finding a great shade match with no testers and poor lighting is difficult. Department stores brands are more expensive, but they have the advantage of providing free testers and the advice of a makeup specialist to help you choose the right color.
The "right" foundation matches your coloring exactly, so there are no telltale signs of demarcation between your jaw line and neck. Always check the shade in daylight, to get the best shade match.
The easiest way to find a match is to apply what you believe are 3 close color matches directly to your jaw line - just draw a small swatch with your finger, of all 3 shades onto your skin. The best color for you is the color that looks invisible on your skin - if the color shows darker or lighter, it's not the right shade for you. Be sure to check the color is daylight to give you accurate results.
Foundation shades vary by manufacturer; so don't be afraid to test several different brands before you buy.
Next, you'll need to determine which foundation form is best for you, depending upon your skin type (i.e.; oily, dry) and how much coverage you need.
Oily - Oily/Combination Skin: Stick with Oil-Free formulations of Liquid Foundations, Liquid to Powder Foundations and Mineral Powder Foundations, which are specifically formulated for oily and combination oily skin types.
If you don't want to shine, choose a foundation that has a "matte" or "oil free" finish. Don't apply a moisturizer prior to makeup application - as it will only serve to help your makeup "slide off", or evaporate during the day.
A pre-makeup primer, like Ale xis Vogel's Secret Perfection Primer de-shines oily complexions and makes foundation wear longer. Applying a loose powder after a liquid foundation application provides much longer wear - especially if you powder throughout the day as needed.
Normal skin: Any foundation form - liquids, powders, and mineral powders work well with normal skin types. Choose a formula that feels comfortable on your skin.
If you need minimal coverage, a tinted moisturizer followed by powder, is a good choice, especially during hot weather. A nice powder to try is Alexis Vogel's Pressed Powder in translucent shades.
Dry skin: You'll need to choose a foundation that camouflages dry, flaky skin. A good choice would be a moisturizing form of liquid foundation or a cr