Dunno if it's been said already as I've not read all the pages, but definitely keep your wits about you. Common sense I know, but it feels like there's a lot of angry cunts on the roads out there to piss off cyclists. And plenty of zombie drivers, as I call them, who just don't seem to notice you and so pull out of side streets and junctions without seeing you, or just don't give you any room as they overtake.
I've been commuting on bikes for years. I don't own a car and so cycle a lot. I've been knocked off my bike 4 times in the last 10 years, the last being a couple of weeks ago, and as usual, a car pulling out of a junction. He was extremely apologetic about it and straight away said he wasn't looking as he pulled out. Luckily I saw that he wasn't looking and so attempted to get around the front of his car, meaning he clipped my back wheel, making me wobble off onto a grass verge where I could commando roll to safety haha.
So when passing junctions and side streets etc, try to look at where the driver is looking as they may move out without seeing you. It might sound like common sense, but maybe not everyone thinks like this and like with driving, you could be the safest and most experienced but yet other people make mistakes/are idiots/zombies or nutters out to get cyclists.
Another one of my favourites (that's resulted with me coming off) is when a driver wants to turn left, and instead of slowing down behind you to wait for you to pass the left turn they want to turn into, they go around you and then turn left right in front of you, or as in my case once before, pretty much into me, making me fly over their bonnet.