I ride under the assumption that every person is actively trying to hit me.
I do not in fact think that this is literally true but by thinking of it this way I’ve avoided a variety of collisions. People (and I’m including drivers, pedestrians and other bikers) just do stupid careless things and in the event of a collision, you lose.
Check parked cars for occupants - driver may suddenly pull out (without signalling or looking), occupants may fling the door open without looking. People with the trunk open may suddenly swing something big out into traffic.
Driveway - someone may back out into traffic without seeing you. Ditto for parallel parked cars. And if you are riding past an empty parking space (especially if parking is hard to come by in that area), assume that someone will focus on the space and just turn immediately in front of you without bothering to check.
Intersections - obey all traffic signals! Stop for the light/sign. Be prepared for people turning in any direction to look right through you or to “take” the right of way. If a signal is just about to change or it has just changed be prepared for people to rush through the orange or to actually blow through the red. Let 'em go.
Pedestrians are often looking for cars but they don’t “see” bikes the same way - I’ve had people step off the curb in front of me (jaywalking), walk out suddenly into traffic from behind a van or other big obstacle, walk backwards into traffic while talking on their cellphone (!), little kids may do lord knows what, etc. A collision between a bike and a person might not be as deadly as bike & car but it can still result in two people getting seriously injured.
In addition to your helmet, lights and “don’t hit me” neon jacket get a nice loud bell. Use it, or call out “On your left” or “Heads up” or whatever - works for cars with open windows, pedestrians/bikers who aren’t paying attention or just can’t see you, etc.
It may seem like a lot but this is all just the same stuff that you should do when driving your car - drive defensively and all that. Only difference is you don’t have 2 tons of steel wrapped around you.
And don’t ride faster than you can safely stop for the conditions - if you don’t leave yourself an “out” then that’s when something bad will happen.