Understand and accept one's differences from motor traffic.
Anticipation: (always needed when one is on the roads)
Motor traffic will do odd things to get around you, and won't always do this in a safe way.
They won't always see you, and I think this genuinely comes down to a pattern recognition issue - motorists are looking for other large vehicles (etc.) in the centre of a lane, because that is what they expect to see. A good example is traffic which is allowed to make right turn with a merging lane. Driver casts a quick glance over the left shoulder and does not see cyclist... Happened to me several times, but anticipation won the day.
In my experience, you need to give time and space to manouvers in traffic, and think further ahead. This is partly a speed issue, if faster moving traffic has to let you change lanes, e.g. to reach a left turn lane.
It is harder (or requiring of an extra degree of nerve) to assert and maintain ones position in traffic when necessary - the vehicle doesn't do this for you automatically by virtue of it's size, so your actions have to count large.
Ed
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Get a bicycle. You will certainly not regret it, if you live.