The most interesting aspect of ring fabrication I've seen, are the ones with a separate ring soldered (by your choice) to the inside of a finished & stone-set ring. If there aren't any inside-rings, the shell (two sides of the ring) of the ring could create a line deep into the person's finger.
So what do these "inside-rings" look like? I have collected some photographs on this topic from my own casino-related line of jewellery, to the more common basic patterns. The whole idea is to prevent deep marks on the finger, from this, a whole slew of patterns came into vogue, ideally created originally by the European jewellers.
What processes in the earlier days did the jeweller cut out 'each & every pattern'? He used to pierce the metal under each stone hole & cut a little pattern with a saw thin #006 or a #009 saw blade, I repeat "under each hole". The labour of this magnitude, was mind-boggling. I'll show you some patterns I used with an Onglette #1 graver! All the little cuts were cut by this setter, using an Onglette #1, then using a slightly modified in the width, Flat graver #40. Even for me, this labour was intensive!!!
Imagine under each & every diamond set hole there was a little hand-engraved or saw-cut pattern! Prior to setting of that one stone, the jeweller would let his saw blade finely cut a design, remove the saw blade & go to the next hole. Insert his saw blade, cut the same pattern, remove his saw blade (if it didn't break), on & on till every hole was pierced, when finished. Then he would give that ring to the setter!
For making pattern in & on the separate inside-ring he would carve out nice little design and then solder with his mouth,blow-pipe or hand-pump torch & solder that inside-ring to the main ring, Remember, this was over 100 years ago & soldering techniques have dramatically changed, now we have CAD!.:>)