The thing to check before anything else is whether it stands on its own or has to lean against a wall. A lot of modern racks, the open metal or wood ones with angled legs, are designed to look a little unstable on purpose, that's the style, but if it wobbles when you give it a firm push with one hand, it's going to wobble a lot more once it's loaded with coats and bags every day. I always test this in the store before I even look at the finish. Press down on one corner. If it rocks, walk away.
Where these go wrong is next to anything ornate. A sleek black metal rack with thin angled legs next to a carved wood console or a traditional rug with a busy pattern just looks like it wandered in from a different house. I learned this one the hard way putting a minimal rack in an entryway that already had a heavy antique mirror and some fussy molding, and it looked like the rack was apologizing for being there. They do best in rooms that are already fairly calm, a mudroom with plain walls, a small apartment entry, a bedroom corner for the next day's outfit. They suit newer builds and renovated rentals especially well, places with clean lines already, and they work year round, though I notice mine gets the heaviest use in fall and winter when there are actual coats to hang instead of just a tote bag and a baseball cap.
On color and finish, I've found the easiest ones to live with are matte black, raw or lightly oiled wood, and brushed brass or nickel, in that order of how forgiving they are. Matte black hides scuffs and doesn't show dust the way a shiny chrome one does, and it goes with almost anything else metal in the room. Wood warms up a space that might otherwise feel a bit cold and works well if you've got other natural materials around. Shiny or polished finishes look great for about three weeks and then every fingerprint and coat zipper scratch shows up under normal light. When you're looking at one in person, run your hand along the finish and check for a texture that will hide small marks rather than a glassy surface that will show every one.
The one mistake I'd steer you away from is buying based on how it looks empty. A rack with three hooks looks clean and spare in a showroom photo, but real life means jackets, bags, a dog leash, maybe a kid's backpack, all on the same day. Count what you actually hang up each morning, then buy for that number plus a couple more, because an overloaded rack with hooks packed three deep is the fastest way to make a nice piece look like a mess.