How to buy an engagement ring

You found your soul mate; now you just need to find an engagement ring that she'll love for, oh, the rest of her life. No pressure. Seriously—once you figure out what she likes (with a little subterfuge), the rest is easy.

From left to right: Me&Ro, $14,600; Martin Katz, $32,500; De Beers, $12,000; Phoenix Roze (from top), $395, $695, $1,500; Nora Kogan, $2,420; David Yurman, $27,000; Ten Thousand Things, $7,200.

There's bafflingly little useful advice out there about buying an engagement ring. Search engines mostly spit back websites that teach you how to become an amateur gemologist, and your best bud just keeps saying he might know someone who knows someone who can get you a deal on a diamond. (He doesn't.)

So we've assembled some hard-won wisdom that will help you get what you want—which, really, is all about what she wants—without getting suckered.

Photograph by David Rinella

1. This Is Gonna Sting a Little

You'll hear that you should spend two to three months' salary on a ring, but that's pre-recession talk.

Be realistic: Start with four to six weeks' worth of paychecks, and be prepared to drop a little extra if it'll get you perfection.

2. Act Like a Cat Burglar

Don't guess at her size—steal one of her rings to have it sized by a jeweler. While you're in her jewelry box, take a few cellphone shots so you can remember what she likes.

3. Turn Her Friends Into Accomplices

Ask her pals (the ones who can keep a secret) if she's dropped any hints—the type of metal, the cut of the stone, a designer she likes. Because she has.

4. Think of Yourself, Just This Once

She might want her wedding band to match her engagement ring—and some couples like their wedding bands to match, too. In other words: Know that if you get her a rose-gold band, you might also end up wearing rose gold.

5. Know the Rules of the Rock

You can get a quick education online about how gemologists grade stones, but after that, you need guidelines: For a diamond, avoid any color grade below H (too yellow) or any cut grade below Very Good (not enough sparkle).

We'd choose a better cut and clearer color over more carats, but if she's expecting a boulder, your choice is made for you.

6. Go Beyond the White Diamond

These days it's cool to put some color on her ring finger; black diamonds, yellow diamonds, emeralds, and sapphires are all fair game as center or accent stones.

Three-Ring Circus

Now that you know what she likes, you can weigh your options.

Traditional: but With A Twist
There's no shortage of designers doing stylish riffs on the classic rock-on- a-ring. You can go full bling with stone-covered bands, try a shape that's more architectural or more hippie-organic, or even get her multiple rings that match—"stacking" is what the Vogue crowd calls it.
Bonus: It's fairly gentle on your savings account. (We won't tell.)

Vintage: Embrace the Quirk
Your girlfriend collects vinyl and has a Pinterest page of Zooey Deschanel's outfits? Then vintage it is. Just know that pre-1930s gems aren't as flawlessly symmetrical as modern ones. "It doesn't mean the stone is cheap," says Henri David, owner of vintage-jewelry-packed Halloween in Philadelphia. "And yes, you can still get vintage gems certified [for insurance purposes]."

Custom: The Perfect Fit
If you like the designer but nothing in the display case quite nails what's in your head, go bespoke. Tell the designer everything you can about your fiancée-to-be: her fashion style, her job, even her favorite season. "One of the best rings I've made was when a guy said, 'My girlfriend loves spring,' " says Brooklyn jewelry designer Nora Kogan. (That's her snake ring in the intro photo.)

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