There's a particular kind of invitation where a plunging neckline feels like the wrong energy entirely, a christening, a work thing with someone's parents in the room, a lunch where you want to look like you made an effort without looking like you're trying to pull anyone. That's when a high neck dress comes out. It does the job of looking finished without you having to think about what's happening underneath it.
This shape earns its place from early autumn through to a mild spring, worn under a coat with boots, or on its own for anything daytime and slightly formal. It's good for occasions where you'll be standing up a lot, talking to people you don't know well, because there's nothing to adjust or tug. Christmas lunches, baptisms, the sort of birthday where there'll be a cake and speeches. Where it struggles is anywhere properly hot or properly loose, a beach dinner, a garden party in July, anywhere you want air near your collarbone. Then it just reads as warm and slightly stiff when everyone else has gone sleeveless.
Be careful what you put with it, because a high neck already does a lot of visual work on its own. A statement necklace on top looks like you're trying to solve a problem that doesn't exist, and most of mine have ended up in a drawer because of that mistake, bought specifically "for" a dress like this and worn exactly once. Big earrings are fine. A heavy coat with a big collar competing at the neck is not, you end up looking like you're wearing two different outfits that met by accident.
Honestly, if you've got a short neck or broad shoulders, have a proper look before you commit, because some of these cuts add height at the throat in a way that can make you look boxier rather than smarter, particularly in a stiffer fabric. A soft jersey version sits better on more people than a structured one. And if you run warm, this is never going to be your easy choice, no matter how good it looks on the hanger.
Over a season, the neckline is the first place to show wear, it's where your jaw and chin meet fabric all day, so look for one with proper binding rather than a seam that'll start to curl after a few wears. Washing cold and turning it inside out keeps the colour further along, and hanging it rather than folding stops that stubborn crease sitting right at the collar where everyone can see it.
A good high neck dress looks like you planned your whole outfit around confidence rather than cleavage, which is a nice thing to be able to say about getting dressed in the dark at seven in the morning.