One thing I do is add a bit of real juice to water. If you start out with a "sweet" juice like apple, it goes a long way with just plain water.
I have a refrigerator with a good filter system for the water & ice, so I use the filtered water with about 25% juice. Cuts down on calories, sugar intake, and the over sweetness of the juice.
If eating tasty stuff is a sin, I am certainly going south.