There are many reasons leather is the best material for everything from day planners to checkbook covers: It's durable and weather resistant, conforms to different shapes, and develops a soft, well-worn feel. But perhaps the best reason is that you can easily fashion little luxuries from it yourself.
Making you own accessories costs far less than buying the finished products, and you can use surprising colors and details that you won't find in a store. Leather is forgiving to work with -- it doesn't fray, so there's no need to finish edges, and if you purchase a 1/16-inch or thinner hide, it can be fed through a sewing machine.
You'll need sturdy poly-cotton thread, a leather needle, and a Teflon pressure foot, which will keep the leather steady. Raise the tension according to your sewing machine's instructions, and make the stitches slightly longer than you would with fabric, to prevent the leather from tearing. Mark lines by scoring with a bone folder before sewing.