The perfect pair of sunglasses can totally rock your summer. It’s the one accessory that instantly communicates style, mystery and even a great sense of humor or a certain seriousness. Take, for example, Lindsay Lohan’s eyeglass choice for a recent court appearance -- an elegant modernized cat eye (Dior’s Bagatelle) that suggested Catherine Deneuve respectability rather than Paris Hilton frivolity.

Effective as they are as a fashion statement and mood booster, designer shades can also make a major dent in your budget, with high-quality lenses running $200 and up. So it makes sense to choose this season’s pair with an eye, so to speak, on fresh new shapes, great frame colors and lens tints, and most important of all, the silhouette that flatters your features and channels your personality. To find that elusive pair, you’ll need an open mind, the stamina to try on at least a dozen pairs, and a sunny afternoon.

Up-to-the-minute Sunglass Styles
Fashion this summer is bare and pared down, making it the perfect time to experiment with fashion-forward frame styles. “The season’s clothes are close to the body, so sunglasses on the other hand can be more exaggerated,” says Cheryl Rosario, a spokesperson for Marchon Eyewear, which manufactures sunglasses for such lines as Calvin Klein, Michael Kors, Fendi, Pucci and Sean Jean. Even if you’re sporting a basic tank and shorts, your shades can add an on-trend spark to your look.

Shades That Kate Hudson and Rihanna Are Rocking
The sunglass mantra for this season: Everything old is new again. “Anything with a retro or vintage feel from the ’50s, ’60s, ’70s and ’80s is really hot right now,” says Eden Wexler, who has the title “Celebrity Shades Consultant” for Solstice Sunglass Boutiques. Kate Hudson, Ginnifer Goodwin, Catherine Zeta-Jones and Gwen Stefani are all working retro-style, cat-eye sunglasses; Rihanna and Kristin Cavallari are sporting old-school aviators; and Robert Pattinson and Marion Cotillard have made funky Ray-Ban Clubmasters look fresh again.

Search out a retro style with accents that keep it looking modern. For example, choose a classic shape (such as cat eyes or aviators) that combines materials (say, a plastic frame and metal arms) or has subtle details (like racing stripes or enamel inlays). Or opt for an old-school silhouette in a fresh, unexpected color. “Cobalt blue, champagne and ivory look more innovative this season,” says David Gonzales, the owner of Fred Segal Eyes in Santa Monica, Calif., who’s known in Hollywood circles as the “Sunglass Whisperer” for his savvy ability to match faces with the right frames. Neon-bright frames make 1980s-style aviators look contemporary, while black and tortoise shell finishes remain perennial favorites.

What’s out
Frames studded with crystals, shields (glasses with one continuous lens instead of two separate ones), big splashy logos and super-oversized styles. “In general, ostentation is out,” says Solstice’s Wexler, a point that Gonzales echoes. “My celebrity customers now look for subtle details that suggest personal style,” he says.

Choose the Shape That’s Right for Your Face
There’s no hard-and-fast rule for choosing frames for face shapes, but the experts suggest these guidelines for finding a flattering pair.

• For round faces: Metal frames with adjustable nose pads will keep lenses from resting on fuller cheeks, says Solstice’s Wexler, who adds that excessively round or square styles will exaggerate facial roundness
• For square faces: Avoid frames that are flat on the bottom, as this will mirror the face shape. Instead, suggests Wexler, “Look for a frame that has some curve or uplift -- that’ll draw attention away from the jawline.”
• For narrow faces: Choose a frame shape that’s rounded or curved to add a touch of width to your face.
• For every face: In general, frames should be wider than the widest part of the face. When trying on sunglasses, do the “smile test.” “If the glasses rise up off your nose bridge when you smile, they’re not for you,” says Wexler. Eliminate pairs that press against your brows, touch your eyelashes, or squeeze your temples or your nose bridge.

Build a Sunglass Wardrobe
“Think of your sunglasses as you do your earrings,” says Gonzales. “They’re like hoops and studs. You wear different things for different situations.” To that end, he suggests at least two pairs: an updated aviator for sporty outings, and frames with a classic Jackie O vibe for dressier affairs. Beyond that -- if it’s in your budget -- the boutique owner recommends picking up a pair that’s just for fun. “Experiment with color,” suggests Gonzales. “Try a champagne frame with a bottle-green lens or a soft-gold frame with a plum lens.”

Gabrielle Anwar’s unique, hot-weather style works in both her major roles -- as ammo-loving Fiona Glenanne on the Miami set of the USA hit “Burn Notice” and as mom to her three kids (Willow, 16; Paisley, 8; and Hugo, 6) in real life. “Fiona has a very utilitarian approach to style,” says Anwar. “If you can conceal a weapon in it and it would function well under fire, then it’s going to work for her. She enjoys exposing the flesh: It makes her seemingly vulnerable, but there’s a lot more to it than meets the eye.”

Between scenes, the 40-year-old actress is often found riding around the set on a cruiser bike in formless dresses and flip-flops. “I think my style may be ‘Bohemian Without a Cause,’” she says of her preferred look. “I like to feel that I can actually parent in the clothes I’m wearing. I’ve collected a bunch of fabrics and colors and textures that I feel are beautiful, and it doesn’t matter what anybody else thinks.”

So what constitutes Anwar’s style? “You don’t have to get dressed up to look beautiful,” she says. “Comfort has a lot to do with it. That, and defining your own style. I’m willing to make mistakes. I’m always more attracted to women who are defining their own look. They catch my eye on the tube or the subway, and I’m intrigued by who they are and why they chose that particular necklace to go with that particular outfit.”

Here are Anwar’s tips on go-to wardrobe pieces for the steamy days of summer:

1. Dresses
I love wearing frocks. I prefer recycling something rather than purchasing new, so I go to vintage stores a lot. It just seems like a better choice. Having said that, I love Rozae Nichols dresses. I find her style very classic and very feminine. She has a casual line, which isn’t really pricey and is as exquisitely made and as beautiful as her couture line.

You’ll find the Rozae Nichols new summer 2010 collection at rozaenichols.com.

2. Flip-flops
I’m 5 feet 3 inches tall, so on the show I have to wear heels to make it in the shot. It would be my head and Jeffrey’s shoulders, or Jeffrey’s head and nothing of me. [Jeffrey is Anwar’s “Burn Notice” co-star, Jeffery Donovan.] In real life, I have a closet full of flip-flops. I do try to keep a very neutral palette. I tend to steer clear of black because it’s so popular and it’s always the choice, so I like to make my own choice. I like neutral colors because I like to feel like I’m existing in a dreamscape. I’m partial to Havaianas because they do some very interesting things with a simple shoe.

Check out the Havaianasus.com for a selection of flip-flops in a dozen different colors, including mint green, pink and marine blue.

3. Summer Night out
I would combine a Rozea Nichols frock, which is very diaphanous and almost ethereal and otherworldly, with flip-flops just so I could stay grounded, although I might have to wear wedges just so I could see what was going on.

4. Bathing Suits
Brazilian bottoms are perfect for every body type. I have sat on the beaches of Brazil, and I have seen every possible imaginable female form in the Brazilian-cut bikini and it works. It gracefully glides the behind in the most flattering position.

Google “Brazilian bathing suits” for links to online stores carrying the swimwear.

5. Jewelry
I mostly wear bracelets. I’m experimenting with earrings, but I tend to feel like a Christmas tree with a lot of jewelry. I usually go for minimal wrist jewelry.

Visit the Web sites of two of Anwar’s favorite jewelry designers, Me & Ro and Jeanine Payer.