I work from home 3 days a week: saves gasoline and money and wear and tear on the car, and work-appropriate clothing.
I take lunches at least 1 of the 2 days I do go to the office. A sammich ain’t free, but it’s cheaper than buying prepared stuff.
We cut down on eating meals at restaurants.
I pay 95% of our bills online, which saves postage (OK, that’s not a huge amount but…)
We do use CF lights where appropriate (they aren’t useful everywhere). We’re experimenting with LED lights in 1-2 places.
We’re keeping on top of all the household bills which isn’t directly saving money (as we don’t really carry credit card balances and have avoided late fees pretty much all along), but is giving us enough better control over the cash flow and better visibility on where the money goes, that we’re whittling down the handful of debts we do have (car loan should be paid off 6 months early, for example).
We refinanced the mortgage, freeing up several hundred a month to apply to other needs.