Nearly every project will require some type of stitching, if the piece is going to be functional. Hand stitching a piece takes time and patience, it is never as easy as machine stitching. You will run into inconsistencies that will reduce themselves with time. The biggest key in stitching is to make sure that you have lined up the punched holes as closely as possible. With thinner pieces of leather, you can often times place the rough sides of the leather together, then punch through both pieces at the same time. Each time you punch a hole, place the first prong of the punch into the last hole that was left from the previous punch as pictured below.
Whip Stitch
The whip stitch is one of the easiest stitches to bind two pieces of leather. To do a whip stitch, you will come through the leather in a downward motion, bring the needle back to your starting position on the next hole and repeat.
Blanket Stitch
To do a blanket stitch, you will make the same motion as a whip stitch, but thread the needle through the loops that you have made as you go.
Cross Stitch
The cross stitch is appropriately labeled, since you are coming across the thread that you just placed. Moving in a similar motion to the whip stitch, you will come backward through the hole that you just made then downward to form an X pattern.
Running Stitch
A running stitch is another basic stitch, but instead of going on the outside of the leather as in previous examples, you simply work the needle through one side of the leather, then back up from the underside as you go.
Back Stitch
A backstitch is similar to the running stitch, but when you come up from the underside, you work your way backward to cover up the gaps that are visible when doing the running stitch. The backstitch is far more secure than a running stitch alone, since it puts a greater amount of tension on both sides of the leather and gives it less gap within the seam.
Saddle Stitch (using two needles)
A more effective way of backstitching through leather is to use two needles in tandem as illustrated below. This gives the leather a figure 8 pattern inside of the stitching holes as you move along the seam.