Shut Off Valve Trim Ring

The last task is checking for leaks!

Use a 1/4 turn ball valve with a compression fitting - no soldering involved.

Yes, the angle stop fixture shutoff valves are usually the last task in a plumbing job. IANAP, but what I have seen with copper piping is a capped stub or closed pipe end is installed prior to the drywall through which it protrudes. Then when the finish plumbing is done after the painting, cabinets, or tile are done when the stub is cut off and the escutcheon and angle stop valve are installed with compression fittings. No soldering involved at this point.

1. Put it there before afixing the valve
2. Use a split ring made for the purpose
3. Drill a pipe size hole in a piece of masonite, cut in half, stick to wall around pipe with some caulk, paint. Won't rust like all the cheap metal escutcheons do.