The passing technique you describe, Mike, is exactly right and totally a kick. You want to be in the left lane for as short a time as possible and the best way to accomplish that goal is to have up a head of steam as you pass. Then it's a matter of timing.
That technique is perfect for the open road but the problem arises when the passing area is short and the sight lines limited. If you know the road, you can hang back, anticipate the upcoming passing area, then time the approach to the slower car figuring no one will be coming in the opposite direction. However, you still have to stick the nose over the line and peek to ensure the coast is clear before committing to the pass.
Then there's the issue of the idiots who won't pull over on the really nice highway here that has no center line and really, really short passing areas. You have no idea if they ever look in their mirror and without the center line, they tend to drift to the left. The technique I use with them is to stick a good portion of my car to their left side so that I can see the driver in his side view mirror. It helps to fake a couple of passes to get his attention and give him an idea of my intentions.
I'm thinking that with a RHD car on that road, when I caught up with aforementioned idiot, I'd probably have to pull over for a time, let him get far ahead, catch him again, drop back . . .