For one thing, a pitcher full of water will help your refrigerator keep your food cool more efficiently, much like how a cold ice pack works in a cooler. Also, whenever you want a glass of water, you won't have to let the tap run for a few moments to obtain a cool temperature, cutting down on waste. Plus you won't need as much ice, which requires energy to make.

Mix two heaped tablespoons of bicarbonate of soda with one tablespoon of white vinegar. Store in an air tight container. For really stubborn spots, use with an old toothbrush and scrub well.