Start with a plain ring stock cut to length.
Using a stamp texture the stock leaving the last 3-5 mm on each end UN textured.
Using pliers roughly round and solder seam. With files and/or sand paper clean up solder seam.
Slide ring onto ring mandrel. Note I do not hold the ring mandrel while I am hammering on it. My ring mandrel is clamped into a steel block clamped to my anvil.
You can also use this method, I used it for years before having the steel block on my anvil. Bore out a hole in a sturdy bench leg that your ring mandrel fits snuggly in.
Not the block added underneath the hole to add bracing to the ring mandrel when you hammer on it.
Again, place your ring stock onto your ring mandrel with your solder seam up. I place my stamp onto the solder seam that we left un textured when we initially textured your ring stock. Strike stamp with your brass striking hammer while holding it steady. Move ring stock and/or stamp a few times to achieve your desired texture. I prefer to do this as opposed to texturing the entire ring stock and soldering it. I find the texture doesn't match up nicely where the solder seam is when you texture the entire piece before soldering. It's not a look I like, so this is how I do it!
Buff, patina and finish ring!