A few other things we do...
1. I try to work from home at least one day a week, which saves at least 50 miles a day on my car, gas, lunch and needing business clothes for that day.
2. I changed to a Diva cup and cloth pads as backup about five years ago and haven't bought tampons or disposable pads since. HUGE savings!
3. I also bought a lot of washcloths and towels at serious discounts and use them almost exclusively in place of disposable paper towels.
4. Following the same principle we also use cloth napkins instead of paper.
5. Common sense: turn off the lights! :)