Real SimpleBeauty Director Didi Gluck answers your Facebook questions.

By Real Simple
Updated November 25, 2013
Nigel Cox

Q. I eat well, take a multivitamin daily, wear gloves while washing dishes and cleaning, use a non-acetone nail polish remover, base coat under nail polish. Why do my nails still split?

A. There are several ways to prevent splitting, says Tracylee, a spokesperson and top technician for Sally Hansen. She recommends starting with a proper waterless manicure. When you soak your hands in water, your nails absorb the water like a sponge. Then when the water evaporates, it takes vital nutrients and hydration with it, which can lead to peeling and splitting. She suggests applying a cuticle-removing cream before using a cuticle pusher around the nails (naturally, she uses Sally Hansen’s Instant Cuticle Remover; $5, To shape nails, file in one direction, starting from the middle of the nail and working to either side (using a sawing action will cause the layers of nail keratin to shred and peel at the nail tip). Avoid filing the “sidewalls” (the straighter sides of your nails); doing so saps nails’ stability and strength, leaving them vulnerable to splitting and breaking. Polish as usual.

To further avoid dehydration, apply a vitamin-enriched cuticle oil two or three times a day (even if your nails are polished), massaging it into the nail beds and cuticles. The oil will be absorbed through the cuticle and hydrate the matrix of the nail (where the cells that become the nail plate are generated), which in turn will ensure healthy growth.

Q. How do I keep eyeliner in my waterline?

A. Unfortunately, when it comes to lining the waterline (aka, the inner rim of the lower lid), there's no ideal answer, says Tina Turnbow, a celebrity makeup artist in New York City. “It’s the eye’s nature to clean itself of foreign objects, so it will tear to try to remove the liner.” The best thing is to get a waterproof kohl pencil, which is formulated for use in this area. Smashbox and Tarte make good ones. But keep in mind that when the makeup migrates to just below your lower lashes, it may look smudgy. If that’s not your style, have cotton swabs on hand to remove excess liner throughout the day.

Q. Any advice on how to treat rosacea or cover it up?

A. Needless to say, the best solution is to visit a dermatologist and get to the root of the problem so you don’t need to cover it up. In the interim, Melissa Silver, a makeup artist in New York City, recommends using a sheer, creamy foundation or tinted moisturizer to cover—but not completely conceal—redness. “This way you won’t need to apply blush on top. Boom! One less thing to do.” Consider applying the product with a brush to help work the formula into your skin if it is uneven in texture as well. If you’re really red, New York City dermatologist Gervaise Gerstner recommends starting with a green-based primer (L’Oréal makes one) to further neutralize redness before applying foundation or tinted moisturizer.

Q. How do I dye my brows at home?

A. You don’t! Well, certainly not with home hair color, which contains ammonia that could drip in eyes and cause damage. Instead, suggests Gina Divine, a hairstylist at the Blow salon in New York City, use a henna kit (available at stores that sell natural products), which won’t harm eyes the way ammonia-based paste can. The downside: It doesn’t last as long as the chemical stuff (three to four weeks as opposed to four to six) and must sit on brows longer to work its magic (45 minutes as opposed to 30). But once whipped up, the mixture stores in the fridge for up to a month. Match the color to your brows, not your hair, for a natural-looking result. Another option (albeit temporary): Fill in brows with a pencil, then top with a powder. The one-two punch of pencil and powder provides color that lasts all day.