I reused the fastening type that I made at my playing cards case.
In fact I even reused its side panel (in this photo, a corner shaped and here straightened again shows with some crincles). The holes were done in 45 degrees with an awl.The sharp edge was cut to angle.
I dumped it in water and smoothened it with short fast moves.
This is how it looks then.
I cut a hole to get the cards out comfortably.
I transferred a few holes from the side panel to the front one..
And then to the back piece.
Fastening was dumped in water and formed to shape to fit the strap.
I marked grooves where the leather would bend.
Soaked in water and let dry in the final shape.
After drying it fits quite well (it took me two tries).
Decoration is done to wet leather with a blunt needle.
I made a basic dyeing. Then I dumped piece of sheet in dark brown, let it dry a bit and lightly with circular moves antiqued the edges.
After that, the edges were painted with dark brown. I glued the fastening on. Needles helped me to get the right position.
I sewed with the same stitch that I used for the playing cards. Sun was painted with acrylics.
My tarot deck is contented.