the story
I came upon an intersection that was green in my direction. One car going the other way waiting to turn left (oh I'm sure many reading know this situation well

I approach and look at her, try and read what she's doing. Decide it's ok, and continue to go through the intersection at about 25-30mph. Only then does she decide to turn.
I slam on my front brake, pull my clutch in, and just look to her left. She had traveled far enough I saw a little gap behind her, and so I aimed for it, tried to not look at her. I think she gunned it, because somehow we did not hit.
I pulled over into a parking lot, turned off the bike, walked around a bit, then went home. My planned hour long ride was a brisk 5 minutes, but it sure was an exciting ride!
the question
What else should I be doing? Two people turning in front of me so soon doesn't seem right. Like my friend just said, go through intersections slower, noted. Other than that, I think I've got the whole arsenal: place hand over front brake while in congested areas, keep scanning all cars, look for signs of what they are doing. Use the traffic signal in the opposite direction and the crosswalk signals to get an idea of how fresh the green light is, watch for people running red lights, keep your priority on problem cars (like left turners), etc etc.