The band is the part you'll feel every day, so start here. A slim, rounded band keeps the focus on the diamond, while a flatter or wider profile looks more modern and a little bolder.

Then choose your metal. We make every ring in 18K yellow, white or rose gold, or platinum. Yellow and rose gold add warmth, while white gold and platinum make the diamond look crisp and bright. Platinum is also naturally white and a little heavier on the hand.

Shape changes the whole feel of a ring. An oval is soft and romantic and lengthens the finger. An emerald cut has a quieter, vintage glamour. Radiant, pear and marquise cuts are a bit more unexpected. Our diamond guide covers each one in more detail.

Then think about size and quality together. Cut matters most for sparkle, and a stone that's eye-clean (no inclusions you can see without magnification) will look just as good as a higher clarity grade. Every Una diamond is lab-grown and comes with an IGI report.

The setting holds your diamond and decides how much of it you see. Claws let in the most light and show off the stone. A bezel wraps the diamond in a rim of metal, which looks clean and modern and protects the edges, so it suits anyone who's hard on their hands.

Multi-stone designs, like a three-stone ring, add side diamonds for extra sparkle. It's also worth thinking about height. A higher setting is more of a statement, while a lower one sits closer to the finger and is easier to live with.

This is where your ring becomes yours. A hidden halo is a row of small diamonds tucked under the main stone, visible from the side. Engraving adds a name, date or a few private words inside the band. And a secret gemstone set inside the band is a small detail only you'll know is there.

Because every ring is made to order, it's worth measuring carefully before you finish. Our ring size guide walks you through it at home.

Remember that fingers are a little bigger in warm weather and smaller in the cold, and wider bands usually need a slightly larger size than slim ones.