"You are not in traffic, you are traffic"
Ever since I read this, my attitude to having to sit in traffic has changed a little. I unfortunately only have a small car, but I like to drive fast and hate being held up by slow drivers. As I drive the same route regularly, I have figured out some ways to make the journey faster.
My main tip is to be really aware. Always pay attention to the car in front, but what else is going on? Are there cars coming from the other direction trying to turn in front of your lane. If so, I would let them turn, as their lane of traffic might be blocking traffic further down. Or is the bus in front about to stop shortly? If so; don't bother trying to get past them sooner, and make sure that you can get past at that point. I try to avoid letting any other cars out into the lane that I am in, unless they are a taxi or a courier as you know that they wont go really slowly and hold you up more.
Another great trick is to notice where traffic lights have a sensor and slow down enough for the sensor to kick in and the lights to change to green. This is both time and fuel efficient as you don't have to stop and change gears a lot.
Nothing is worth having an accident over, so there is no point in taking unnecessary risk, however, on occasion I have deliberately gone into the lane to turn right, and made sure that I pulled away faster that the first car going straight. This is known as 'cutting someone up' and isn't advisable, but sometimes you just have to get passed someone.