When running water to wait for it to warm up, collect it and use for other purposes like watering plants
While waiting for the water from the tap warm up for your shower or to wash dishes, as much as 1 – 2 gallons of clean, potable, usable water rushes down the drain. Put that water to good use around the house! Catch the flow in a bucket or pitcher, and use it to water houseplants or an outside garden, or add soap and use it for mopping. You can even use it to flush the toilet!
Photo credits: Gosheshe, Flickr; Austin Kirk, Flickr