Your guide to the ultimate ‘coastal grandmother’ summer

That’s it. Now you’re getting in the spirit. Let’s get going.

All the vintage pieces that tastemaker and author Mary Emmerling, 79, has been decorating with for decades are looking fresh and friendly to millennials. “I think a lot of them want it because of the way the world is right now,” she says. “They are thinking of staying in more and enjoying family more and wish they had the time to do it.” She has a younger friend who recently told her: “ ‘I just want to wear cashmere sweaters and jeans and go to farm stands and barbecue.’ ”

Emmerling, who actually is a grandmother with a coastal home in Bridgehampton, N.Y., has written 36 design books, including “Mary Emmerling’s Beach Cottages: At Home by the Sea.” She suggests starting with “that big, cozy, comfortable sofa and lots of cushions and lots of pillows,” then adding a chunky, sturdy wooden coffee table. Put up a hat rack for straw hats, ponchos and beach blankets. And don’t forget the sisal carpeting on the stairs. “Otherwise those clogs make too much noise,” she says.

The style doesn’t have to break your budget. Beachy touches can be as simple as baskets for stashing keys and toilet paper. Big pieces of driftwood or large shells make great door stoppers. Emmerling likes small, inexpensive rag rugs that you can easily shake out. (Grandma Mary’s tip: Shake first, then toss them in the dryer on the “air” setting to get them clean and smelling fresh.) One way to get that coastal-grandmother look even in the tiniest urban apartment: curtains blowing in the breeze. “I buy old lace whenever I find it and then do half-curtains on the bottom of the windows,” she says. “I still want to see the sky.”

Nothando Nyathi, 27, who pens the blog Musings of a Young Homemaker, says the look is for people of all ages and locales. Although she lives in landlocked Staffordshire in England, she has been embracing the aesthetic and sharing photos on Instagram of her own coastal-grandmother moments: shopping at open-air markets, enjoying an alfresco cheese board and setting an outdoor table. An easy design tip? “The coastal grandmother always has fresh flowers in blue ginger-jar vases,” she says.

Cookbook author Gaby Dalkin, 35, who espouses a California-inspired, laid-back approach to cooking and entertaining, says the coastal-grandmother style — which puts less emphasis on fancy preparations and more on enjoying food with guests — feels particularly right during these stressful times.

Her dream dinner? A slow-roasted salmon served with cherry tomatoes tossed in “an incredible vinaigrette” and served with a salad of butter lettuce and avocado, she says. And dessert would be similarly fuss-free: She would have “some cookie dough already in the freezer,” so she can bake off fresh cookies at a moment’s notice. Table-setting, too, should be easy-breezy. Bottles of wine and platters of food make for a pretty table, and a plop-it-in-a-vessel floral arrangement and some linen napkins (rumpled ones are fine) complete the look.

Dalkin suggests that aspiring coastal grannies stock up on basic baking ingredients, so they can whip up a batch of scones or a simple cake if the mood strikes. A homemade vinaigrette stashed in the fridge can top pasta, vegetables or meats, she says. (She swears by her basil version.)

Adopting the coastal grandmother’s kitchen attitude is key. “She’s learned a lot in however many years she’s been alive,” Dalkin says. “She knows what’s up. She knows how to shop and how not to stress about entertaining.”

Fashion designer Eileen Fisher, 71, has been producing what is arguably the uniform of the coastal grandmother since 1984.

What’s not to like? Long tunics, cuddly cardigans and simple T-shirts in beige, white and black are her signature looks. And, of course, lots of comfortable elastic-waist pants. Her clothes are on the more expensive side, but coastal-grandmother wannabes might consider the fact that investment dressing is better for the planet than fast fashion, and that this brand is big on organic fabrics and sustainable work practices.

“This kind of dressing lets you focus on your work and your life. We aren’t spending hours fussing with ourselves and our clothes,” Fisher says. “These clothes say: ‘Don’t look at my high heels or my tight outfit. Look at me, the whole being.’ ”

For Fisher, who has two children but no grandchildren, the coastal-grandmother thing has come full circle. In May, she posted a video on Instagram on the lush lawn in front of her house on the Hudson River, dressed in her own brand of off-white organic cotton jeans as Natalie Cole sang “This Will Be (An Everlasting Love),” a staple of coastal-grandmother playlists. Fisher double-dips on the lifestyle by renting a house in Amagansett, N.Y., each year. “Yes, I do go to farmers markets, and I walk on the beach in a long, white linen dress that’s about 20 years old,” she says.

The least-expensive way to be a coastal grandmother is to cop the attitude. She has a no-apologies mind-set, and she doesn’t care about rings on the coffee table or whether you think she should touch up her gray hair. (She would rather hit up a flea market or bike around town on a Saturday than sit at the salon.) She doesn’t chase trends; her bathing suit might be sun-bleached, and her nightshirt might be an Oxford button-down from her third husband. She knows not to sweat the small stuff.

Enjoying the hard-won mind-set of not giving a flip — although the coastal grandmother we’re channeling might use saltier language — is the ultimate lifestyle upgrade.

For Nyathi, the appeal of the lifestyle is that it helps you see otherwise mundane tasks such as shopping and cooking as pleasurable activities to savor, not as chores. “As much as it is a trend now, it really involves simple day-to-day lifestyle activities,” she says, evoking another phrase that has taken off on social media: “It’s all about romanticizing your everyday life.”

So try turning down the invite to the brunch you didn’t feel like going to, anyway. Spend the afternoon with a jigsaw puzzle, or tuck into a trashy novel instead of the podcast your friends are talking about.

As for Emmerling, she’s spending her 80th birthday in July at a Stones concert in Paris.