The contents of a cosmetics drawer are often a woman's dirtiest secret. If not properly cared for, the nature of cosmetics - tubes and jars of colored powders, pencils, loose brushes and tubes of liquids - can lead to an ugly mess. Our panel of beauty experts provides strategies for making the cleanup as seamless as the application.

The shelf life of any product depends on how you care for it after it's open, says Rita Brown, principal makeup artist for Shu Uemura in Pacific Heights (shuuemura-usa.com). Protect products from direct sunlight and heat, which can alter color and consistency. When cleaning, scan products for expiration indicators. Check surfaces for oils, dust or bubbles. Take a whiff: Strong, unusual odors are good signs that it's no good. If the shape, color or texture has changed, toss it.

At right are more maintenance and expiration tips from Brown.

- Lip products. Lip gloss keeps about six to 12 weeks. Wipe the wand with alcohol about every two weeks to keep it sanitized. (This helps maintain the consistency of the formula, too.) Lipsticks keep a bit longer, about four to five months. Swipe the tip along a paper towel occasionally.

- Eye products. Sharpen eye (and lip) pencils between uses and these products should keep through the end. Mascara is at its best before the 13-week mark. Keep it from drying out sooner by avoiding the urge to pump the brush, which pushes air into the tube.

- Foundation and powder. Change out these items seasonally to match shifting skin color. For powders, use a brush instead of a sponge to minimize the transfer of dirt and oil onto the product.

- Don't brush it off. Wash makeup brushes two to four times a month, says Annie Ford Danielson, San Francisco-based Benefit Cosmetics trend artist. (benefitcosmetics.com). Rinse with warm water, careful not to submerge the entire brush. Lather in a conditioning shampoo and rinse. Gently squeeze excess water and fluff. Lay brushes on a flat, toweled surface and let dry.

- Maintain your tools. Use a fine-tooth comb to strip strands from hairbrushes once a week, says Desmond Crosby, color specialist for Sephora in Union Square (sephora.com). Then rinse the brush under warm water to remove residual hair product. Take your tweezers to a cutlery for sharpening and tension adjustment, so you can grab those baby-fine hairs. Use alcohol to sanitize and eliminate mascara buildup from your eyelash curler.

- Keep cream fresh. Skin care products usually last six to 12 months once open, says Cris Thorngate, manager of the apothecary Kiehl's in Pacific Heights (kiehls.com). Stick to the expiration dates to ensure you receive the formula's full benefits, especially when it comes to sunscreen. With jars, use sterile, plastic spatulas to eliminate the transfer of bacteria from fingertips to the product.

- Make scents last. Fragrances generally last as long as three years but can keep as many as five if stored inside the box, away from light, says Nancy Lueck, Bloomingdale's West Coast public relations director. Extend the life of fragrance by applying with the stopper. Direct contact from fingertips to bottle can transfer oils, ultimately altering the fragrance.

- Don't just toss it. Check with cosmetic companies for recycling incentives. MAC Cosmetics, for example, offers a free lipstick for every six containers dropped off (maccosmetics.com).