This trick is older than I am, but figured I'd post it anyways.
To make your water taste better without adding calories, sugar, or anything all you need to do is:
1) Fill an XL pitcher of cold water
2) Add ice cubes
3) Slice very thin your favorite fruit and add it to the water for flavor (some obvious exceptions - Ie don't add banana)
The fruit will add flavor (Don't eat the fruit) and barely any of the sugars will dissolve ( Less than 2g of carbs)
Enjoy !