Monopoly has some good points, but there is something I feel needs to be pointed out. Leather has a smooth side and a rough side. When you look closely at the smooth side of a piece of leather, it almost appears to have large scale-like things on it that are a result of it being folded. Make sure to use very very thin lines of a darker color than the rest of it, and smudge them in a little to make them look like creases. And the rough side of leather almost looks like a little brown forest, using a few dark spots and light spots almost like salt and pepper right on top of everything Monopoly said can add a little more depth and realistic flair to your leather.