Mix up your materials and textures.
What's cooler than a leather jacket? How about a leather jacket with a massive amount of fur trimming. Robb Stark realizes that any true King of the North can't be monotonous in his battle tactics nor his steez. So instead of sticking with one consistent material and texture, Robb mixes it up for a richer, fuller look. If a dude looked this slick, wouldn't you follow him into battle against the Lannisters?