Here is the process I use to make cue rings.
The rings shown are butt rings to fit a 19mm core and are made from of Merbau, the inlays are Tasmanian Oak.
They are cut on my CNC mill using a 4th axis to index between cuts.
I use a high speed spindle rather than the mill spindle as the extra speed gives better slot finish.
After cutting the slots, the edges of the slots are sanded, then epoxy is added and the inlays put in place. A wrap of electrical tape will ensure nothing moves until the glue has set.
Then the piece is moved to the lathe where it is trimmed to diameter, then the individual rings are faced off with a parting tool.