Earthing conductors in metal back boxes

[pls1]

What is the usual procedure for terminating earthing conductors for sockets with metal back boxes say on a ring main. Is it best practice to terminate both earth cables into the earthing terminal of the back box first and then run a single conductor (sleeved) to the faceplate (regardless if it is metal or plastic).
The alternative would be to run both conductors to the faceplate first and then a single conductor from the faceplate to back box.

 

[chivers67]

I run them to the face plate and a single to the back box. I terminate the back box first as I find it easier to do it that way. If the back box has a fixed screw it's normally sufficient as once the screw is in place it is then earthed but some say it's better practice to have a permannent cpc to it.

 

[RF Lighting]

You must terminate the circuit CPCs to the socket front.

If the box has a fixed lug, then no connection to it is required, but many still like to add it anyway.