Yup, everything that applys to your car, applys to your home. Grill blocking the grills in the crawl spaces, smoothing over the windows with weather stripping and doors, putting a piece of insulation over the attic opening, insulation over and under your living spaces. A timer to cycle your hot water heater to the time when its most needed as well as turning down the temp on it. Setting your hvac for a lower temp and making sure the filter is clean.
One of my projects is to make a solar window heater.