The short sleeve dress gets filed as the boring, sensible one, the thing you buy when you can't be bothered to think about an outfit. I used to agree with that, right up until I noticed it was the dress I actually reached for on the mornings I had the least patience for getting dressed. It's not exciting. It is, almost every time, correct.
The difference between a good one and a bad one shows up fastest at the sleeve itself, which sounds obvious but gets ignored constantly. A cheap one cuts the sleeve too tight and too short, so it digs in and rides up on your upper arm within an hour, and the seam puckers because it's been stitched in a hurry. A better one has a slightly looser sleeve with a proper hem, cotton or a cotton blend with enough weight that it skims rather than clings, and a hem on the skirt that's been turned twice rather than overlocked and left to curl. Buttons, if there are any, should feel like they'd survive a washing machine rather than a single wear. If you're starting with none of these, go for a plain midi in a colour you already own three other things in, navy or a soft rust rather than anything print heavy, because the print version dates while the plain one just gets re-worn. It pairs with almost everything already hanging up: flat sandals and a denim jacket for the school run or the shops, a blazer and trainers for something that reads as trying without actually trying, or opaque tights and ankle boots the second the temperature drops, so the one dress covers three seasons rather than being packed away after August. That's the bit nobody tells you when they sell it as a summer dress.
Over months it tells on itself honestly. Good cotton softens and keeps its shape, the colour fading slightly in a way that looks lived in rather than tired. The cheap stuff pills under the arms first, always, and the hem starts to sag on one side before the other, which is somehow worse than sagging evenly. Wash it cooler than the label dares you to, hang it rather than tumble it, and it'll outlast most things in a rotation you actually wear rather than admire. Iron the collar if there is one, nobody looks at the rest.
It will never be a dress that turns heads on its own, and if you want drama you'll need to add it with shoes or a coat, because the dress itself isn't going to supply it.