Three details do most of the work. Milgrain is a line of tiny metal beads along an edge, which softens the outline and catches light like fine stitching. Filigree is open scrollwork that lets light and air through the metal. Engraving cuts patterns into the surface of the band or the head. A vintage inspired engagement ring might carry one of these lightly or layer all three, so decide how much ornament you want to live with every day.
A useful test is to imagine the ring with your everyday clothes rather than on a wedding day. Delicate milgrain alone reads quietly at the office; a band covered in scrollwork and engraving makes more of a statement.
Step cuts and soft cushions suit the look best. Asscher and emerald cuts, with their long, mirror-like facets, bring a geometric, old-fashioned calm, and an asscher also shows a windmill pattern from above, though it faces up smaller than a round of the same weight. A cushion's rounded corners and broad facets give a soft, pillowy glow. Rounds work too, especially framed by milgrain. Browse asscher cut diamonds if the windmill effect appeals.
Step cuts show inclusions and color more than brilliant shapes, so set the clarity floor at VS1 or VS2 for an emerald or asscher center. With a cushion or round, an eye clean VS2 or SI1 is usually enough. Color depends on the metal: platinum and white gold reveal warmth, while yellow and rose gold forgive a warmer stone and add an antique glow of their own. Rose gold vintage settings are a good example of warm metal doing that work.
Ornate engagement rings usually look best with a wedding band that either echoes the detail or steps back from it. A slim band with matching milgrain ties the pair together, while a plain polished band gives the eye a rest. If you are shopping for vintage wedding rings to match, check that the band follows the engagement ring's outline, since a straight band can leave a gap under some heads and a curved one closes it. Engraving on the inside of the band is another way to tie the pair together, a private line that echoes the detail on the outside. For finished period looks, see vintage engagement rings for women.