Attempt 1: a simple steel ring. Not particular difficult, or interesting. I gave up without even completing the finish, you can still see some machine marks. This design is not "substantial" enough.
Attempt 2: a steel signet ring with a wide flat and shoulders. I began with a 30mm mild steel rod I turned out the inside of the ring, then milled and ground down the other surfaces. After a few hours work, I had a ring that looked more like a one-finger knuckle duster.
I had a professional engrave the initials into the centre, whilst I attempted the framing lines. The difference in skill is quite evident. The significant advice from the professional engraver was: use a different material, the steel was much, much too hard. That reality really should have dawned on me, with all the work I was doing to the steel, the turning, milling and mostly, the grinding, had hardened the steel dramatically. The engraver found even those initials incredibly hard to finish with his available tools.
Attempt 3: a brass signet ring, with a more rectangular flat, and higher shoulders. I ground this entirely by hand with a Dremel, as I don't have any 30mm brass rod to turn (I do have 50mm brass rod, but that wouldn't be an efficient use of that stock). My goal for attempt 4 is to smelt some of my brass swarf (offcuts from lathe/mill) and to pour rings in sand moulds myself. Until that, this is my best attempt. Whilst there are still some machine marks, one more polish should give it a mirror finish, ready for engraving and hard gold plating.