Pick one up and you can usually tell straight away from the weight of the fabric alone whether it's going to behave. A good A line skirt has a bit of body to it, enough that it holds its own shape off the hanger rather than flopping into a limp triangle. You want the waistband to feel sturdy under your fingers too, not that flimsy single layer of jersey that twists the moment you sit down.
This shape earns its spot across most of the year rather than being for one specific moment. A denim or cotton version takes you through spring and into a mild autumn, worn with bare legs and trainers or with tights once it turns. A heavier wool blend version is the one for winter, worn under a coat where the fullness doesn't matter because nobody sees it until you take the coat off indoors. For anything smarter, a satin or crepe version in a darker colour does the job without you having to think about it twice. In the ordinary wardrobe it sits well with a plain fitted top tucked in, because the shape only really works when there's a visible waist underneath, and it's forgiving over boots, trainers or heels depending on what you're doing with the rest of the day. A fitted jumper works for the same reason. What it doesn't love is anything else with volume on top, a loose blouse over it and the whole thing stops looking like an outfit and starts looking like two separate decisions.
If you've got none of these and you're starting from scratch, go for a mid weight cotton or cotton blend in a length that hits just below the knee, in a plain colour like navy or a soft grey rather than anything with a print. That length and that fabric cover nearly every situation you'll actually find yourself in, work, casual, slightly smarter, without you having to own three different skirts to manage it. Avoid anything too stiff to begin with, a skirt that stands away from your legs like a lampshade is a specific taste and not a starting point. Honestly, the cheap ones in a good fabric often outperform the expensive ones in a bad one, which tells you where to put your money.
Give it a year or two of actual wear and the fabric softens in a way that suits the shape, the fullness drops slightly and sits closer to the body, and the waistband loses that stiff new feel. A cotton one will have faded a touch at the front where your bag sits against it, which somehow makes it look more like yours and less like something off a rail.