One of the things I noticed is that as "smaller" participants in traffic get faster, it gets exponentially harder to account for them. Eg. runners are harder to see because you need to be watching a much wider angle that is more likely to be obscured by something or other. Bicycles even more so.

If you are not starting from a stop, my solution to avoid any close calls has always been to hover my foot over the brake on top of making my turns as perpendicular as possible (there are other reasons to do that too: I see cars tilt into the oncoming traffic lane, which slows oncoming traffic down and delays their left turn, making for fewer cars passing at that traffic light and increasing congestion). If there's any potential a pedestrian (think a small child or a short person) is obscured by any other object (a car, a street corner...), slow down even further even if you've got right of way.