When I first moved in, the propane dealer estimated that we would need a 500 gallon tank, and that we would fill it two or three times a year. I looked at the three delivery charges for the year and we were using over a 1000 gallons of propane! The next spring we put in a chimney and bought a wood stove. I had a log load delivered and cut and split seven cords, sold three for the price of the whole load. A few weekends of sawing and splitting = free wood heat!
I had the propane truck fill the 500 gallon tank and it lasted a year and a half! We switched to two hundred gallon tanks and are now using 400-500 gallons a year. Other ways I saved on propane was to stop using the gas fireplace, drying clothes on the line, switching to a multi-fuel range, and turning down the thermostat on the domestic hot water heater.