The mid thigh length gives this blazer the potential to create a long dark frame. Stand several feet from the mirror and look first at the outer edges rather than the details. The left and right fronts should travel downward in smooth, nearly parallel lines. They can skim the body, but they should not swing into dramatically different curves.
Now turn slightly to each side. Look for pooling at the waist, a lifted back hem, or a front edge that twists. These signs do not make a garment universally bad. They simply tell you that this particular knit is no longer producing the continuous, controlled line that makes it useful for a Dramatic Classic outfit.
Build the base beneath it with restraint. A black or charcoal top and straight trousers can extend the vertical line, while a crisp ivory shell can create one deliberate contrast inside the black frame. The aim is not to remove contrast. It is to place contrast where the jacket can contain it.
Keep the remaining details quiet while you judge the blazer. Choose a clean neckline, a defined trouser crease or straight skirt line, and one precise accessory. Multiple soft layers, loose scarves, and several small focal points can disguise whether the blazer itself provides enough order.