The short answer on White Poplin Dress: pick one anchor piece, keep the palette to two colours, and let the shoes decide how formal the whole thing reads. Proportion does more than colour: volume on top wants something narrow below, and the reverse. Repeat one element, a metal, a texture or a colour, and an outfit looks deliberate. Lining is what stops a cheap fabric reading as cheap. The groups below run from the decision that matters most to the ones you make afterwards.

What decides this is shoulder fit, length and how the fabric moves. Everything else is preference. Two from the first group show the range: Duffield Lane's Ivy Dress in White Peony at $111, and Akira's PARTY FAVOR RUFFLE MAXI DRESS IN WHITE at $130. The first is the easy entry point; the second is where the money goes. A dress that fits the shoulders can be taken in anywhere else. One that does not, cannot. Check where the waist seam sits on the model against your own proportions. A higher price mostly buys materials and finishing, and occasionally it buys nothing at all.

A belt turns a shapeless dress into a deliberate one. Let the dress be the loudest thing you own that day. From the second group, Duffield Lane's Mackinac Dress in White with Navy Toile ($188) is the one that earns its place, because it works in more than one context without being restyled. The third group is smaller and deliberately narrower, dresses, for the decisions you make after the main one. None of this needs the whole group. One piece from each is usually enough.

There are 20 dresses here from 14 brands, $60 to $520, all in stock when this was written. We would not buy all of them, and neither should you. White Fox Boutique's Anouk Knit Midi Skirt Off White at $60 is the low-risk way in, and MATTERS's Bea White Dress at $520 only makes sense if this is a category you already use constantly. On white poplin dress specifically: the difference between the top and the bottom of this list is real but smaller than the price gap suggests. Nothing here is included because it is famous, and price is not used as a proxy for quality anywhere on this page. If you take one thing away: one considered purchase beats three hedged ones.