Saddle stitch consists of two rows of simple running stitch and is sewn using two needles. This gives a strong and even stitch which is suitable for most leather-working.
Thread a needle onto each end of a long piece of thread. Make a line of holes in the leather using an awl and pass one end of the thread through the first hole (figure 1). Even up the length of thread on each side of the leather. Stitch with each needle using simple running stitch - pass a needle from front to back through the next hole (figure 2) and then pass the other needle from back to front through the same hole (figure 3). Continue along the line of holes. Finish off by passing both needles onto one side of the leather and tying the two threads together (using a reef-knot).
figure 1 | figure 2 | figure 3 |