There are many practices followed at my home which are sustainable in the definitions of design communications, but generally, they are just a way of life in many of the small towns of the countryside in the state of Bihar. Some are traditional practices, some are due to the absence of luxury of choice, some just due to resource constraints.
First of all, our home is well ventilated and requires the least amount of energy to function. All LED bulbs light only after sunset. Our home doesn't have air-conditioning, or geysers, or coolers, or any such extreme energy-draining heavy appliances. We are not consumed by the trend of consumerism, and we purchase things on the basis of needs, and things get replaced only if broken beyond the scope of repair. 'Unnecessary' expenditures, if any, requires divine interventions -literally it's reserved only for round the year poojas.
It is a traditional practice, my mother will make quilts and blankets using used clothes and sarees. All the old sarees are laid down flat and then quilted together to make quilts, durries. If time permits and the help of cousin sisters are also available to her, then they would also make Kantha embroidery on these quilts. Other old clothes (all of the cotton, with trims and accessories detached from them) are used as fillers in making Rajai (blankets).
Other than these, we use a two-wheeler for private transportation, and public (non-flight) transportation is the first choice for any sort of long-distance travel. All the food grains as well as many of the vegetables we eat are from our own fields. Packaged and junk foods are almost non-existent in our lives. We bathe using a bucket and mug, not in the shower. Personally, I never let any 'wastewater' discharged out of the water filter to get into drains, they are collected in buckets and used in toilets or to water flower pots.