Ok, I have no idea if this idea saves you money, but it does save water.
I fill our water bottles and water jugs and keep them in the fridge. I read online that if a fridge is full of items and water bottles and it will take less energy to power the fridge. If nothing else, this tip helps my will. I no longer turn the tap on and let it run until my water is cold. Storing water bottles in the fridge at least keeps my water cold.
It pays to be frugal.