For straight grooves, I use the Bevel tool, and some simple extruding and scaling operations. However, I also want to place an oblique line on a ring (so seperate the ring into two piece for a 2 coloured ring). Furthermore, not only straight but also wave-shaped grooves as follows. (from the wedding ring front view)
I want to ask for help on how to place an oblique line and wave-shaped grooves on ring.