You are not adding an accessory. You are editing the architecture.
Fabric weight matters here more than pattern. A fourteen-momme silk will collapse inside the loop and lose the V-shape within minutes. You need enough body for the drape to hold its form when you move — sixteen momme at minimum, or a twill weave that gives the silk a slight memory. The Valkyrie works particularly well for this because the satin finish catches light at the fold point, which emphasises the dimensionality that the whole exercise depends on.
Colour is secondary, but it is not irrelevant. The principle is simple: the scarf should be close enough to the coat’s value — its lightness or darkness — that it reads as part of the same composition, but different enough in hue that the eye registers the layer. A teal scarf inside a navy coat. A warm bronze against charcoal. You want harmony, not contrast. The coat is the room; the scarf is the object inside it that makes you look twice.
