Insulate Your Water Heater
Purchase a water heater blanket for your water heater and it will pay for itself in a matter of months.
According to the Iowa Energy Center, an insulating blanket will cut energy loss 25% - 45%. Assuming you spend $25 per month heating your water, it is safe to say you could save $5 - $10 per month just by installing one.
Not everyone needs a water heater blanket. New models of water heaters are already insulated. How to tell? Simple... just place your hand on the outside of the water heater. If it's warm, then it needs to be insulated.