How to layer a sleeveless dress starts with the dress itself. Check the armhole, shoulder width and fabric before adding anything. A clean armhole can sit over a close-fitting T-shirt or fine knit, while a wide opening needs a layer that will not bunch beneath it. The dress should still skim the body when another piece is underneath, especially at the waist and underarm. COS options in this edit range from $110 to $189, with midi and maxi lengths that can support several combinations. A sculptural jersey shape already has visual presence, so a plain base layer usually keeps it balanced. A lighter cotton or linen dress can take a more visible shirt or knit, provided the neckline and sleeve do not fight the dress's lines. Consider the season through fabric as well as coverage. Linen softens and creases with wear and washing, while cotton jersey often follows the body more closely. Try the complete combination before deciding on size. Raise your arms, sit down and walk a few steps. If the dress pulls at the chest or the underlayer twists, changing the base layer may solve the problem more effectively than sizing up the dress.

A cardigan is useful when the dress needs warmth without losing its shape. Choose a shorter style if you want to show the waist or keep a long dress from feeling heavy. A longer cardigan creates a relaxed column and can work well over a straighter midi, but it needs enough room at the armhole to avoid catching on the dress. COS cardigans in this selection cost $139 to $429. Merino is fine and relatively thin, so it can sit more neatly over a dress than a bulky knit. Cashmere is warm for its weight and can make a lighter dress practical in cooler rooms, though it deserves gentle care. Think about fastening as well. Leaving the cardigan open preserves the dress's neckline and creates a vertical line, while closing it can turn the cardigan into a defined top layer. If the dress has pleats, appliqué or another prominent surface, keep the cardigan smooth so the textures do not compete. A patterned knit can work when the dress is simple, but repeat one colour from the dress to make the combination feel connected. The most useful layer is one you can remove easily without disturbing the fit underneath.

For cooler weather, a jacket changes the mood of a sleeveless dress more sharply than a cardigan. It adds structure at the shoulder and can make a bare-armed summer shape work in cooler weather or a more formal setting. A short jacket is often easiest with a fuller skirt because it defines the waist and keeps the proportions clear. With a long, straight dress, a longer coat or jacket can create a continuous line instead. COS jackets in this edit are priced from $229 to $299. A trench brings a lighter, directional layer, while boiled wool feels denser and more protective. A bomber introduces volume and a casual finish, so it works best when the dress is not already highly rounded or oversized. A belted style can give shape to a simple dress, but avoid tightening it over bulky knitwear. Check the sleeve and armhole before buying: the jacket must accommodate the dress without pulling across the back. Colour can either separate the layers or quieten them. A close tonal combination looks streamlined, while a contrast jacket clearly marks the dress as the base. Use the hem as a final check, since a jacket ending at an awkward point can interrupt the dress's line.

We would begin with a close, comfortable base layer and add warmth in stages. A cardigan keeps the dress visible and is easier to remove, while a jacket gives stronger shape and protection. Match the thickness of each layer to the dress's armholes, then test the full outfit in motion before committing. Sleeveless does not have to mean limited to one season. The best combination should feel easy to wear. If you take one thing away, let the dress lead and choose layers that support its shape rather than hiding it.