For years I thought a cotton hoodie was the colour equivalent of giving up, the thing you wore when you couldn't be bothered to think, and it took a grey one with a decent weight to it to show me that giving up and getting dressed properly aren't opposites. The right one still looks like you made an effort, even though you made none.
It's not the answer to everything, mind. Stand behind a counter all day doing anything fiddly and a boxy cotton hoodie will annoy you, cuffs catching on things, hem riding up when you reach overhead, the hood sitting like a collapsed tent down your back the second you take it off. It's a sitting down or walking about garment, not a working one, and it does nothing for you under a coat with any structure, you end up with two different necklines fighting at your throat. Wear it somewhere that wants you to look like you tried, a dinner, an interview, anywhere with a dress code even a loose one, and it reads as exactly what it is, which is comfortable, not considered.
A good one and a bad one can look near identical on a hanger and feel like entirely different garments on. The cheap version is thin, slightly see through under a bright light, and goes bobbly under the arms after about four washes because the cotton's been spun loose and cut with something synthetic to bring the price down. A proper one has weight in the hand, a brushed or looped back if it's meant to be warm, a flat smooth face if it's meant for layering, and the ribbing at the cuff and hem has actual stretch left in it rather than going slack by the second wear. The drawstring matters more than it should, a flat cotton tape that sits nicely against the chest rather than a round cord that twists itself into a knot in the machine. Stitching at the shoulder seam should sit flat, not puckered, and the zip, if there is one, should be a proper metal or heavy plastic tooth, not the flimsy sort that catches the fabric the first week you own it.
Don't put it anywhere near anything with a sharp shoulder or a tailored collar, it flattens both. Skip the heavy statement necklace too, the hood eats it. And any fabric with real shine, silk, satin, a high gloss nylon, sat next to brushed cotton just looks like a mistake, the textures argue rather than sit together.
Get the weight right and it's one of the few things that looks as good doing nothing as it does doing something. That's rarer than it sounds.