Susan Greenwood has a job a million women would die for: She selects custom diamond engagement rings for E.E. Robbins. Her job requires impeccable taste, and as a former fashion model and previous owner of the trendy Paragon boutique in Belltown, she also knows how to shop. So whether you’re looking to propose or nearing your 30th anniversary, take a few tips from Greenwood.

Know the four C’s: (1) Cut (maximizes brilliance); (2) clarity (fewer markings = higher rarity); (3) color (clearer = costlier); (4) carat (more carats = bigger rock).

For clueless guys: Pick out a diamond set in a simple solitaire; surprise the love of your life, then come back with your fiancée to choose the ring. “Seventy-five percent of our customers do it that way so the girl can have the style that suits her. Most guys love seeing the girls pick out the ring, and they become the hero twice.”

Where to pop the question: Greenwood says, “If my husband proposed to me in public, I think I would have died; but when you really think about it, it doesn’t matter what’s around you because if you’re with the right person, the whole world will disappear around you.”

Most romantic proposal: Greenwood says sometimes low-key is best. She remembers one couple that came into the store to pick out a ring, obviously madly in love. Earlier that morning, when they woke up in bed, he turned to her, stared deeply into her eyes, and told her he couldn’t imagine his life with out her and asked her to marry him. Swoon.

Craziest proposal: Greenwood recalls one man who tried to be a literal knight in shining armor, but realized the costume was slightly heavier than he anticipated. Not only could he barely walk, but mounting the horse was almost impossible.

Best anniversary gifts: Don’t be tightly wound to anniversary gift-giving standards; your presents should be personal. “My husband and I follow the traditional model, but always add our own touches, like a stationery set with a Mont Blanc pen.” Also don’t be eager to buy diamonds right away. Go out to dinner on your first anniversary, and wait for the rocks until it’s a really big occasion, like your first baby or your 30th anniversary.