The hard part is not choosing the ring. It is finding out the size, the shape they want and the metal they wear, without asking any of the questions that would tell them what you are doing.
It is all solvable. Some of it needs a few weeks of lead time, so the earlier you start the less you have to improvise.
Size, without asking
The best method is to borrow a ring they already wear on that finger. Not any ring: fingers differ, and a ring from the right hand will usually mislead you by half a size or more. Take it for an evening, measure the inside diameter across the middle in millimetres, and put it back before it is missed.
If borrowing is not possible, the next best thing is a person. Mothers, sisters and close friends often know, and they are usually delighted to be asked. They are also, in our experience, better at keeping the secret than people fear.
Failing both, err larger. A ring that arrives slightly loose can be worn on another finger for a day and quietly sized down afterwards. A ring that will not go on cannot be worn at all, and the moment is not improved by that.
Shape and metal, without asking
Look at what they already own. The metal that dominates their jewellery box is the metal they like, and it answers the yellow, white or rose question without a single conversation.
Shape is harder because most people own no diamond to compare against. Two things help. Elongated cuts such as oval, marquise and pear read larger for the same weight and suit people who want presence. Round brilliants are the safest choice by a wide margin, and there is no shame in safest when the stakes are this high.
If they have ever pointed at something in a window or paused on a photograph, that is worth more than any amount of inference.
Give yourself time
Every piece we make is made after it is ordered, and that usually takes about ten days before it ships. Add delivery on top. If there is a date you are working toward, count backwards from it generously, and write to us before ordering if the timing is tight so we can tell you honestly whether it is possible.
Ordering three days before you plan to ask is how people end up proposing with a photograph.
The part worth being clear about
We do not accept change-of-mind returns, because nothing exists until you order it. This is not a shop where you buy three and send two back.
That sounds unhelpful in an article about surprises, so here is the practical version: talk to us before you order rather than after. Tell us what you know, what you are guessing at, and what they wear. Sizing in particular is a five-minute conversation that saves a resize, and we would much rather have it up front.
If you would rather not guess at all
Plenty of people buy the moment and the stone separately. You propose, then you choose the setting together.
It is less cinematic and it produces a ring they actually want. We have no stake in which route you take, but we would gently point out that the second one has a better record.