Shape is the first decision and the most personal — it sets the ring's whole character before a single setting is chosen.
The field, quickly
Round — maximum sparkle, maximum price, never wrong. Oval — today's favorite: elongating, brilliant, great spread. Cushion — soft romance, best value in brilliants. Princess — crisp modern square. Emerald — glassy step-cut drama for clarity lovers. Asscher — Deco square with windmill facets. Radiant — brilliant sparkle in a trimmed rectangle. Pear — sculptural teardrop. Marquise — royal spread champion. Heart — literal romance, needs 0.75ct+ to read.
How to choose
Match the hand (elongated shapes lengthen), match the jewelry she wears (minimal = round/oval/bezel shapes; vintage = cushion/Asscher), and when torn — the oval is the modern default for a reason.