Below you can see most of the steps I take in making a fine watch strap.  The first step is the selection of the leather.  Occasionally, I will find and use a piece of pre-dyed upholstery or heavy garment leather that appeals to me, but my straps are primarily made of 4/5 ounce vegetable tanned tooling leather.  The leather is cut to length and width and assembled to its final dimension while forming the spring bar and buckle tunnels.  Next, any tooling is performed, and the holes for the buckle and stitching are made.  Dyeing and finishing is next.  Depending on the desired finish, this may be a  single standard color, a custom blended color, or multiple colors layered.  After dyeing, a protective topcoat is applied.  Finally, after 24 hours for the finish to cure, the strap is hand stitched using a double needle saddle stitch.  Somewhere along the way, usually at the end since I tend to forget it quite often, I make a matching keeper.  Sometimes I get a bit carried away, and the keepers become a little project unto themselves.  After all assembly and stitching is done, the strap gets a final buffing of the finish a thorough inspection, and is ready to go.  From start to finish, a strap is on my bench for 2-3 days.