good post greg.

similar to your hard shoulder one, when waiting on a main road to turn right at a junction into a side road, don't have the wheels turned right in readiness as if you're hit from behind you will be pushed into oncoming traffic.

when moving to the left or right for whatever eason, as well as having checked the mirrors regularly before and during the manouvre, look over your shoulder to check the blindspot just before moving. i learnt this as the 'lifesaver' move on a bike, but applies equally to car driving as well.

there are the more obvious ones like using indicators, moving over lanes etc, but they're all covered by the general rules of the highway code. the fact that people don't really follow them shows that they are not taught properly and / or properly enforced by the lack of traffic police these days