As others have said, make sure to take account of your route. I would suggest actual empirical notes, so you're no basing your route decisions on individual, anecdotal experiences.
One of my key tips is to take advantage of light sensors. In Los Angeles, it is nigh impossible to not get stuck at a light. So you are either idling for a while, or shutting your engine off while waiting. If you don't want to do the latter, make sure your tires roll to a stop on those black, tar cuts in the asphalt. They are usually circular or hex-/oct-agonal in shape. By stopping on them, you trip a sensor that tells the light to go green sooner.
__________________
|