We take a large glass of water with us to bed every night. Rarely do we ever finish it, I am sure we are not the only ones.
What do you do with the water the next day? I either pour whats left into the animals water bowl, or if that is full, use it in the plants around the house. This might now seem like much, on a daily basis, but on a monthly and yearly basis it is quite a bit.
There are small things like this you can do around your house that will impact your wallet and the earth in a big way.