You should have a Ground Bus, mounted in your cabinet, Metal to Metal no paint under it, this is where all the Ground wires are to be connected, at the same point, the snips are the ideal, you can also use a stud and stack each Ground connection, with star lock washers and nuts for each connection, this is messy and not as good, compared to a Bus type bar, which you can make it yourself
So, each item that has a Ground wire connection, all should have there own Ground wire connected to the Bus
Shields connect direct to the Ground Plane, P-Clamp type is the best, or EMI Glands for shields, saddles type clamps work but not as affective