That is the approach I take. As other riders have said, I look for indicators, wheel angles all sorts. When a car pulls to a junction I try to make eye contact with the driver and I watch the wheels to see if they are still rolling.
Also, i never move into oncoming traffic.
I've never disagreed that some people do not ride safely but by contrast rees_a is clearly of the impression he doesn't need to look out for bikes and if he kills someone then that's a good thing. He lives in London, it isn't as though he is unaware of this happening like someone in a rural area who might not have a lot of standing traffic issues so there is a duty of care owed by car drivers too.
If the CBT was part of every driving test (for cars and bikes) then car drivers would be a lot more appreciative of the issues.
m.
EDIT. What a silly follow up post.
Here's what you are saying:
"The sooner people realise that some people drinking leads to alcoholism the better. Ban drink for everyone!"