Been thinking of remodeling? Winter is the time to get your price quotes and do the work. Since contractors have it slow this time of year, you'll end up reaping the savings.
Ask your electric and/or gas company for an energy audit or go to energystar.gov for tips on doing your own (under Home Improvement). Often your electric company or gas company will do this for free.
Now would also be a good time to clean your fridge or freezer. (I don't mean the inside, though that might be good too). Pull your appliance out, unplug it and vacuum or brush the condenser coil. This will reduce the energy it needs to run. Repeat every six months.
Also, if your freezer contents are running low this time of year (or anytime), fill plastic bottles with water and put in to freeze. Leaving them will prevent the freezer from working just to keep the air cold, saving on your energy bill.
Hope any of this helps.