When you replace a toilet, install a low-consumption model or a water saver. Standard toilets use 5 to 7 gallons per flush; "water-savers" use 3 to 4 gallons per flush; and new low-consumption models use 1.6 gallons, or less per flush. Until you replace your toilet, put a plastic bottle filled with water in the tank to cut down on water needed for a flush.
Match the size of the pan to to your stovetop heating element; more heat will get to the pan and less will be lost to the surrounding air. A 6-inch pan on an 8-inch burner will waste over 40% of the energy used.