A lot depends on whether it is veg tan or chrome tanned leather.
( If you don't know what you have. You can test by wetting a small area and moulding it over something, leave it to dry. If it keeps the moulded shape it's veg tan. You can't mould Chrome)
You can use something like
Tokonole to burnish the edges. Paint it on and while still damp, rub it with a smooth glass, wood or bone slicker. Chrome tan will smooth and firm a little, but Veg tan will get a high shine on it.
You can emboss on veg tan but not on chrome tanned.
The thin leather will look better with hemmed edges and you can sew that on a machine if it's man enough, with a needle for leather.
If you have the patience, you can hand sew. Like others have said. You need a hole punch tool and needles.