If in doubt always take the safest option - parking across the road. This works really well in township areas and also prevents the rubber neckers - althogh we still provide a crew member to redirct the traffic and provide the alternative route.
On the open road we have also used this tactic, however have also utilised the group vehicle for protracted incidents and placed that 100 meters down the road (or further if there are bends in the road), in the middle with it's beacons and headlight flashers operating - pointing towards the oncoming traffic - this slows them down very quickly, as it's hard to tell the difference between a police vehicle and command car at a distance
Years ago when on a strike team in the Flinders, the police set up a radar in the main street of Wilmington (the forward control point and staging area) They operated for an hour or two a day, got some excellent pinches and news quickly travelled that they were there and booking people - problem solved!