Choose a needle specifically designed for leatherwork. These needles tend to leave a smaller hole and prevent seam rips in the future. In a well-lit area, hold up the needle so the end with the hole (also known as the eye) is sticking up and facing you. Carefully guide the end of a piece of thread through the eye and feed several inches of thread through the opening.
Prepare the the two sides that you want to sew, so you can have access to the top and bottom of the leather. If the rip is on a couch cushion, remove the stuffing from within. If you are working on a jacket, remove the liner if possible. This will allow you the full range of motion needed to tightly seal the tear.
Begin by inserting the needle a few centimeters from the bottom of the tear, into the leather and under the tear. Insert the needle on the underside of the leather on the opposite end of the tear so there is a stitch combining both sides of the tear. Gently pull these together.
Repeat your first stitch over again, only moving up the line of the area you're sewing a tiny bit. Keep the stitch tight.
Sew in a straight line along the tear until you come to the end. Tie a knot on the underside, and you are finished.
