Sophia Loren famously called the fountain of youth “your mind, talents and creativity.” Si, signora , but a fab shirt helps—at least according to some retirees.

“I won’t stop dressing well. That’s like stopping joy,” said Judy Pariser, 65, a former nurse in Harlingen, Texas, who recently visited New York on “a fashion inspiration trip.”

Pariser and her cohort are “shopping more than previous generations did in retirement,” said Michael Clinton, 70, the CEO of Roar Forward, a venture that offers “business intelligence” to the over-50 set. But shopping more is not always shopping well, and some “classic” pieces look as dated on retirees as a “Love Boat” rerun would on prime time TV. So we asked chic seniors and fashion pros how to appear stylishly relaxed, not tired. Here, their advice.

Older: Clingy Black Knits

Wiser: Vibrant Wool Sweaters

Entering retirement means “a new life is beginning—not ending,” said New York stylist Gayle Perry. But wear all-black and you might appear sallow instead of chic. Try navy, or even better, bright hues like azure , green , orange and scarlet. Pure wool can help regulate body temperatures better than synthetic blends.

Older: Thin-Frame Glasses with Narrow Ovoid Lenses

Wiser: Cat-Eye or Aviator Frames

Glasses can be an “instant lift for your face, and the easiest way to contemporize your look,” said Rachel Fanconi, the London stylist for Dame Helen Mirren, 79. For glasses and shades alike, she suggests cat-eye frames “with a gentle uptick at the sides” to provide a face-lifting illusion—no Boca Raton plastic surgeon needed. Not into the feline gaze? Try   aviators for a similar “awakening” effect.

Older: Threadlike Necklaces

Wiser: Statement Charms on Wide Chains

Thicker chains work well with thinner skin around the neck, while charms make a plain outfit into a statement. “Put a fantastic pendant with a sweater and you’re dressed,” said Pariser. Her favorites come from Susan Alexandra, a Manhattan jeweler known for whimsical, gold-enameled pieces.

Older: Floppy Ballet Flats

Wiser: Lug-Sole Loafers

These chunky-soled shoes are staples for Prada and Gucci. They’re also ankle-stabilizing, said Kim Larson, 71, a philanthropist and retired urban planner in Mt. Kisco, N.Y. “You’ve got comfort paired with versatility,” she said. Former “What Not to Wear” host Stacy London, 55, noted lug-soles have one more advantage: “A bigger shoe makes your body look smaller.”

Older: Sleeveless Dresses

Wiser: Dresses With Three-Quarter Sleeves

When stylist Perry worked at Calvin Klein in the 1990s, sleeveless frocks were infallible. Now? “They might look dated on mature women.” Perry recommends trying three-quarter sleeves, which reveal an elegant flash of skin below the elbow. “It’s very alluring,” she said. Plus, it showcases a vintage watch with easy glamour.

Older: Fluttery, Swirl-Print Blouses

Wiser: Crisp, Solid Button-Ups

“A solid shirt frames the face,” said Cheryl Sparks, 68, a retiree in Providence, R.I., who runs the “mature style” Instagram handle @_IfItsTuesday_ . “Go for poplin, which is crisper and more structured,” she said. Choose an oversize fit, then undo a button or two to elongate the neck. “It’s fashion,” Sparks said, “without fuss.”

Older: A Neon Sun Visor

Wiser: A Sporty Straw Hat

Playing pickleball? Visors are great. For pursuits with less thwacking, dermatologist Dr. Ellen Marmur recommends straw hats with UV-blocking fabric to shade the scalp, face and ears from sun damage. Plus, you’ll look cooler while keeping cool.

Older: Velour Joggers

Wiser: A Wide-Leg, Slightly Cropped Pant

Yes, part of the joy of retirement is ditching stiff office slacks for pants that let you breathe. Instead of rumpled joggers, consider cotton pants tailored with a wider leg. They combine the roomy comfort of sweats with the versatility of elegant trousers. Look for an  ankle-length hem to help elongate the leg, and pair them with a casual top during the day, or with a jacket and silk shell at night.

Hair and Makeup by Karol Rodriguez; Styling by Caitie Kelly; Talent is Anya Longwell for Q Management

The Wall Street Journal is not compensated by retailers listed in its articles as outlets for products. Listed retailers frequently are not the sole retail outlets.