Simple method,well, this is MY method anyway and it hasn't failed me yet .
Cut away the tape from ALL metal contact areas on your pickguard that would otherwise require grounding. That includes all pots, switch, pickups etc. Then run ALL ground wires (switch, pickups, bridge or tremblock AND shielding) to volume pot. You can treat the tone pots as one ground, ie. run a wire from farthest tone pot to the case of the next one then to the vol pot. Lastly, run a wire from the vol pot casing to output jack. To ground your shielding you can crimp an eye lug to a wire and then use a small wood screw to hold the lug in contact with the copper tape in the bottom of your control cavity, the other end is soldered to the vol pot casing.
Tone pots should also be grounded to themselves. Third lug is pushed up in contact with the pot casing and then soldered. Thats the surest way I know to ground a guitar.