File tips into a "squoval" (square with rounded corners), the most youthful shape, says Lisa Logan, a celebrity manicurist. Because nails tear easily after 40, wet a glass file (the least abrasive filing option) and use it to shape your nails.
We like Swissco Emery Glass ($7, sallybeauty.com). For unruly cuticles, soak your tips in water for a minute, then gently scrape any dead skin off the nail bed with a tool like Apt 5 Cuticle Pusher ($5, drugstores).
"Ridges are nails’ version of wrinkles — and yes, you get more of them as you age," says Richard Scher, MD, a dermatologist who has special expertise in nails. To smooth out ridges, lightly sand the nail surface with a buffer. (Do this only once a week; excessive buffing will eventually thin and weaken the nails.) Try CND Glossing Buffer Block ($7, goindulge.com).
After applying a base coat, brush on a pale polish in soft pink, cream, or sheer white — the light color cancels out the yellow tones in your nails and brightens the look of your hands. "Darker colors are fine too. Just steer clear of anything with too much yellow or orange; it can make aging skin look sallow," Logan says. Finish with a clear topcoat.
Sally Hansen Insta-Dri Nail Color in Rose-a-Go-Go ($5; drugstores). Not so skilled at the DIY mani? This lacquer’s new, extra-wide brush makes application easier — two strokes and your whole nail’s covered. (Bonus: Drying time is just 60 seconds)