By Christina Shanahan
Updated May 15, 2015 @ 8:15 am
Credit: Rex USA

The season's hottest swim trend is a major nod to Jane Birkin's breezy beach looks from the 1970s. Teeny bikinis in bold colors with cool, crochet details are dominating, and it's a throwback that we can get on board with. Need some inspiration? Check out Triangl's neoprene version (below, left, $89; and Kiini's cool colorblock style (below, right, $285; Then, take this styling advice from Olivia Wilde's wardrobe whisperer Karla Welch and let your free-spirited summer begin—VW Splitty not included!

Credit: Courtesy

Mix and Match

"On the beach, you have the freedom to do whatever you want with your look," says Welch. "You could go crazy and mix patterns with swim separates, or get a really fun sarong to pair with your suit."

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Shop it: H&M sarong, $13; J.Crew bikini top, $62; J.Crew bikini bottom, $44;

Choose a Cool Cover Up

One way to let your '70s suit take center stage, even when you venture away from the shore, is to choose something gauzy and sheer so that your bikini peeks through. "I love a white, gauzy peasant blouse as a cover up," says Welch. "Just make sure it's one you don't mind getting wet!"

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Shop it: Melissa Odabash, $200;

Add Bold Accessories

"A big floppy hat is so seventies, especially a woven style," says Welch. "Then you’re getting your sun protection as well." When it comes to sandals, she recommends strappy gladiator flats, like the ones by Ancient Greek Sandals.

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Shop it: Nordstrom crochet rafia hat, $48; Ancient Greek Sandals, $143;

Don't Forget Your Shades

"If you’re going for that full-on '70s vibe, go for an oversized brown or black frame to complement the glamour of the suit," Welch suggests. "But if you prefer a John Lennon-style graded frame, that works too!"

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Shop it (from top): Marc by Marc Jacobs, $120; Tory Burch, $175; BP., $12;