The thing nobody tells you about a jacket until you've worn it properly is that the collar tells you everything in the first month. A good one softens exactly where your neck turns, keeps its shape everywhere else, and still sits flat under a scarf in November. A bad one goes slack at the collarbone within three wears and never recovers, no matter how carefully you hang it. You won't spot this in a changing room under shop lighting with your coat already half off. You spot it on the fourteenth commute, when it's raining sideways and you need the collar to actually do something.
Get the fit right by checking the shoulders first, not the waist. The seam should sit exactly on your shoulder bone, not an inch down your arm, because a dropped shoulder on a structured jacket looks sloppy rather than relaxed, and you can't fix it with tailoring without spending more than the jacket cost. Sleeves want to end at the wristbone with enough room to push up for washing hands or holding a coffee without the cuff gripping. If you're starting from nothing, go for a plain jacket in a neutral, something cotton or a simple denim rather than anything cropped or heavily quilted, because a mid length neutral works under a coat in winter and on its own from April onwards, while the cropped and the heavily padded versions are both one trick ponies that only suit certain tops and certain weather. Pair it with high waisted trousers and a plain top and it does the job instantly, then once you trust the fit you can add a leather or a denim version for contrast, knowing the shape already works on your frame.
Over the months it will tell you the truth about the fabric. Good cotton or denim softens and creases in a way that looks lived in rather than tired. Leather darkens slightly at the elbows and cuffs, which most people end up liking more than the stiff original finish. Quilted and puffer styles flatten a little with wear and need shaking out and occasionally refilling at the shoulders if you can, rather than washing on a hot cycle, which kills the loft for good. Spot clean where you can, wash cold and rarely, and let zips and poppers do their job rather than forcing them when cold fingers make everything feel stuck.
Tomorrow morning I'd put it over a plain jumper and straight leg jeans, with boots that can handle whatever the weather actually decides to do.