Cotton shirts suit anyone who wants one solid, grown up piece that doesn't ask much of them in the morning. If you run hot, or you're someone who irons under duress and resents every minute of it, go for something with a bit of give in the weave rather than the stiffest poplin on the rail, because that version will crease the second you sit in a car and stay that way all day. If you genuinely never iron anything, ever, be honest with yourself before you buy the crisp white one, it will look sad by eleven in the morning and that's not the shirt's fault.
I reach for mine most in that stretch between seasons when a jumper is too much and bare arms feel wrong, so early autumn mornings, cool evenings in June, the kind of March day that can't decide what it's doing. It layers under a jumper with the collar out, which does a lot of visual work for very little effort, and it's the thing I throw on over a plain t shirt and jeans when I want to look like I tried without actually trying. For work it does the job under a blazer, for weekends it does the job knotted at the waist over a vest, and it's forgiving of a slightly bigger lunch than planned, which cotton poplin is not always known for. It sits well against denim, against tailored trousers, against a plain skirt, and it's one of the few things I own that looks equally right with trainers and with proper shoes. Before you buy, check the weight of the cotton by holding it up to the light, a lighter weave will show your bra through it, which is fine for some wears and not for a work meeting. Check the buttons too, the cheap ones crack down the middle after a handful of washes, and look at the collar stand, if it's floppy out of the packet it will only get floppier.
What I like about a good one is how it changes with wear rather than just wearing out. The first few washes it's a bit stiff and new feeling, almost formal, and then somewhere around wash fifteen or twenty it softens properly, goes slightly thinner under the arms, starts to feel like something you've actually lived in rather than something you bought. The collar loses its sharp edge, the white goes gently off white however careful you are, and honestly that's the point it gets good, not the point it gets replaced.