1. Check this: refrigerators suck up a whopping 20% of your household electricity use. Time to turn them down! Aim for somewhere between 38-42 degrees in the fridge, and 0-5 degrees in the freezer. If you've got an energy saver switch, make sure it's flipped on. Doors should be sealed tight: to test, stick a dollar bill between the gaskets and close the fridge door; if the bill is hard to pull out you're in good shape. If not, it's time to replace the gaskets.
2. Wash only full loads in your dishwasher (yet another reason to learn to pack them efficiently!), and if you have time, let them air dry by turning off the drying cycle manually—this can save 20% of your dishwasher's total electricity usage.
3. Don't use hot water when doing the laundry. If you must, try warm water, though in most cases cold is probably just fine. Make sure that the amount of water you're using corresponds with the size of your laundry load.
4. Lower the temperature of your water thermostat to 120-130 degrees (any lower than that might backfire on you, since you might end up running out of hot water).
5. Clean your air filters regularly. Air conditioners have to work a lot harder to circulate air through filthy filters, which is a totally unnecessary electricity drain.
6. And while you're sitting in front of the computer, turn on the sleep mode, so it's less of a power drain when you're not using it. Windows users can do this via the control panel, while Mac users can find energy saving settings under system preferences in the apple menu.