For my home I too have turned the water heater down. Replaced all light bulbs to the CF bulbs. I replace my furnace filters regularly. I use my water from RO for my washer as well. I only use my AC when it is really humid at night. I also have reptiles so don't like the AC on too much. Once summer hits I turn all my heaters down in my tanks. Me and my wife prefer the dark so the only lights on at night are from the fish tank or the TV. I made sure to buy a energy efficient AC last year. I replaced two wooden doors on my house to better insulated steel doors. Took down the window blinds and bought double coated curtains to hold heat in for the winter. I live in like a 100yr old house, so basically anything I do is an improvement. I want to get a electric instant hot water heater, new windows, a new roof, and put spay insulation in the walls.'
My tanks I try to use low wattage pumps and powerheads. I cut my light cycles back by 2hours on both of my setups. I took down a 20gal freshwater setup to cut back a little. I do group buys with my friends to save cost on shipping and to get better prices. I just added a canopy over my 90gal setup to help with evaporation. Put all my lights on timers so that I dont have to deal with the lights manually and forget about them. I buy made phyto instead of buying store brands. Win a ton of food at the swaps so I dont have to buy food for most of the year. I am sure that there are a few things I am missing but we all should make a good effort to cut cost and energy use.