I make double layer gun belts. It's not really just lined but two full thickness belts glued and stitched together back to back.
After cutting the straps, I lay one aside then cut, slot, punch and skive the buckle end and cut it to finished length.
Then I'll make the belt keeper.
I'll lay out where the inner layer'll end on the buckle end then I'll predye the seam.
The end of the inner layer gets skived, beveled, predyed and burnished where it meets the outer layer. This gives it a smoother transition where it attaches to the outer layer.
Then the two straps get glued together back to back.
I'll lay out the stitch lines and do any tooling after the glue dries. Tooling after the two straps are glued together prevents the top strap from distorting.
After the tooling's done I'll poke the stitch holes by marking them with a pricking iron then making the holes with a stitching awl. Also I'll make the adjustment holes with an oval punch and cut the inner layer to match the outer layer.
Then it's time to bevel the edges and dye the belt. Burnish the edges and buff the belt but don't finish coat yet.
Sit back, relax and get ready to spend 6 hours or so hand stitching.
After the stitchin's done, then it's time to do the finishing work.