Choosing an engagement ring

Like wondering whether she'll say yes isn't stressful enough. You're also supposed to select and purchase a ring that fits her magnificent personality, her singular style and her, ahem, finger? Help! We called on the Engagement Experts (engagementexperts.com) to do just that. If you're still flummoxed, ask her (trustworthy) friend to advise. — Heidi Stevens

Step #1: KNOW THE FOUR C's

CUT: Proportions determine brilliance and sparkle. Grades are assigned based on these. (Don't confuse cut with shape.)

Shallow: Looks bigger from top, light escapes out the bottom

Ideal: Light enters, exits through top; most expensive

Deep: Light exits the sides; usually a higher carat weight

CLARITY: Ranks internal imperfections, called inclusions (I). Only grades I 1-I 3 have inclusions visible to the naked eye.

COLOR: A letter-grade scale rating the absence of color.

CARAT WEIGHT: This is how much the diamond weighs. 1carat = 100 points. Bigger number = higher cost. (Bigger isn't always better.) Also consider the top of the diamond in millimeters, which determines how big it looks in the setting.

Step #2: SHAPE, SETTING

Shape: Rounds are the most popular, but pick what she'll love.

Setting: Anything your heart desires. Top metals are yellow gold (10K, 14K, 18K), white gold (needs replating over time), and platinum (hypoallergenic and most expensive).

Step #3: KNOW YOUR GIRLFRIEND

Ask yourself: What do her favorite jewelry pieces look like? Are they more contemporary? Classic? Vintage looking? Are they big and bold pieces or more understated? How does she dress? Would you classify her as bold, earthy, vintage, classic or elegant?

Step #4: KNOW HER RING SIZE

If she wears a ring on her ring finger, grab it next time it's off. Place it on a piece of paper, run a pencil around the inside and take the drawing to the jeweler, who can turn your reconnaissance into an actual size. Or, go costume jewelry shopping. Have her try on a variety of rings on different fingers, keeping in mind which one fits her ring finger. Buy it for later reference.