Another way to help your refrigerator to be more energy efficient is to make sure that everything is properly covered. Liquids, if containers aren't tightly sealed, will evaporate
The same holds true for food that you put in the fridge. Always make sure that the food containers are closed tightly and that the food has cooled down. If you place hot or very warm items in the fridge, that too can make your refrigerator work harder. Allowing food to cool before placing it in the fridge is an excellent idea, provided you don't let the food sit out at room temperature for too long!
So step #4 is:
Always make sure food and liquid containers are tightly sealed when in your fridge.