Great visual indicators of how to occupy a lane

It should be noted that there is some disagreement as to how to accurately describe the primary position, as it obviously changes when you pass a parked car, etc. I think it's important to describe it as relative to other traffic, not to the kerb or other fixed markings. My favourite formulation is 'just to the right of the left-hand tyre tracks' (and vice versa for the US etc.). But, as I say, there is some disagreement.

Bang on. Too many get lazy and think "this is the position" not realising the dynamic nature of roads means it is a constantly changing thing.