The moment it clicked for me was standing in a hallway at half seven, already running late, pulling on a navy jumpsuit I'd almost sent back because it looked shapeless on the hanger. Shoes on, belt pulled in, done. No skirt to check in the mirror twice, no top that had ridden up by the time I got to the bus stop. One zip, one decision, out the door.
A plain, dark colour is the easiest thing to live with by a mile. Navy, black, a deep bottle green, they do all the thinking for you and they hide the bits that a jumpsuit can be unkind to, mainly the stomach and backside in one unbroken stretch of fabric. Viscose and viscose blends drape well and don't cling, which matters more than people realise once you're sitting down for three hours at a table. Linen looks lovely for about forty minutes before it creases into a map of wherever you've been, which I still buy every summer and still complain about every summer. A playsuit in a crisp cotton holds its shape and doesn't need much ironing, but it will show every crease from being folded in a drawer, so I hang mine now rather than fold them, which took me embarrassingly long to work out.
Where it goes wrong is the obvious bit nobody tells you until you're already stuck in a toilet cubicle undoing the whole thing to go to the loo. A jumpsuit with a fiddly back zip and no give in the fabric is a nightmare after a glass of wine, and I've got no patience left for anything I can't get in and out of quickly. Anything structured or boned through the bodice is also the wrong pick if you're after comfort rather than shape, it'll hold you beautifully for the first hour and dig in for the rest of the night. And if you're short, a wide leg cut in anything but the right length will eat you alive, I learned that one the hard way in a changing room with a hemline pooling round my ankles like I was wearing someone else's trousers.
Before you buy, check the crotch depth sitting down, not just standing in the mirror, because that's where a bad one reveals itself. Check the fastening, whether it's a zip, buttons or hooks, and whether you can actually manage it alone. Check the fabric doesn't need a strapless bra you don't own.
Would I be able to get this on and off by myself in a hurry, and sit down in it without regretting everything?