The strap holders are made from left overs from the straps. The ends needs to be burnished and holes are marked with the pricking iron. It is not necessary to have two lines of stitching on each side but I think it looks good. When I'm sewing it I might questions my choice but that's too late now!
4 strap holders cut from the straps.
Burnish ends and scribe lines for the pricking iron. 4 and 12 mm from edge.
Place pricking iron right at the edge of the strap.