Welcome to the forum!
You've probably read by now that the #1 thing you can do to save fuel is adjust the nut behind the wheel, especially since you're doing an urban type commute.
You need to get some instrumentation in the car so you can monitor your fuel consumption on the fly and make your commute a daily "high score" challenge. Unfortunately, your car is too old to use a ScanGauge or equivalent (works on 1996+ OBD-II equipped vehicles only).
Research the "MPGuino" for an alternative to the ScanGauge. (Note: I'm not sure if the developer is still selling completed units.)
I'm sure by now you've already seen these:
65+ Efficiency Mods
100+ Hypermiling Tips