The short answer on What is an Alt Girl is below, and the honest version is that it depends on two or three things rather than one. The short version usually matters less than how the thing is used now. Most house signatures were practical marks before they were status ones. The shoulder seam should sit on the bone, not past it. The groups below run from the decision that matters most to the ones you make afterwards.

What decides this is shoulder seam, sleeve length and opacity. Everything else is preference. Two from the first group show the range: fahertybrand.com's Laguna Linen Bandeau Top - Sunbeam Stripe at $98, and Elie Tahari's Embroidered Chiffon Shirt at $227. The first is the easy entry point; the second is where the money goes. The shoulder seam should sit on the bone, not past it. Hold it up to the light. Opacity is the thing product photography hides best. A higher price mostly buys materials and finishing, and occasionally it buys nothing at all.

If the top is the point, keep everything below it plain. From the second group, Faherty's Herringbone Studio Jacket - Polar Night Herringbone ($239) 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, shorts, 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 pieces here from 16 brands, $42 to $398, all in stock when this was written. We would not buy all of them, and neither should you. nobodyschild.com's Brown Double Layer Henley Top at $42 is the low-risk way in, and SAME LOS ANGELES's Silk Halter Top (Butter Yellow Polka Dot) at $398 only makes sense if this is a category you already use constantly. Read as a set, they get you close to What is an Alt Girl without any single purchase being compulsory. 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.