Sustainability/Conservation and waste reduction (personal)
New plastic garbage containers can be transformed into rain barrels to irrigate lawns. Use of aerators reduce water use.
Inline water filters de-chlorinate tap-water and remove excess contaminates. This eliminates bottle water waste, and trips to the water dispenser.
Non-disposable air filters save money and reduce disposal. It may not be proven, but it seems to save on energy usage by eliminating air drag. Included are air conditioning filters and car intake filters.
Food-grade glass jars can be washed and reused as drinking glasses.
LED light-bulbs are usually free of hazardous materials, and they save substantially on energy costs.