Watch that idle time: Letting your engine idle for more than 30 seconds will burn more gasoline than restarting the engine, so turn the engine off if you expect a lengthy wait.
Take a break from driving. Consider walking, biking, taking a bus or carpooling whenever feasible. And if you have more than one vehicle, drive the one with the best gas mileage whenever you can.
Use pressure cooker: Using pressure cooker saves the LPG consumed & your gas cylinder runs for a longer time.
Say No to Polythene bags: Polythene bags are a complete menace to environment through its whole life cycle. They block air and hence does not let your fruit and vegetables breathe.
Plant trees in waste lands: Small pieces of unused land should be used to plant trees.