Add lemon or drink unsweetened tea. If you're going to add sweetener, use Stevia, since "fake" sweeteners can actually cause you to gain weight, by making you crave more sweets.
Stevia is all natural and has zero calories.
Try herbal tea! There are alot of different herbs which tastes wonderful without any added sweetener. And it can count as your daily water intake because they aren't dehydrating:-)
I use cucumbers and try a pretty glass
I go for the fresh 100% fruit juices, either Apple or mango & orange. Check the container doesn't say " made from concentrate" and check the lable it's 100% fruit. I use the Innocent brand. smoothies is another option if you like them you can make your own 0:)
I use great value version of crystal light and then crystal lights pomtini. Also you try lime instead of lemon.
I like Zero, which is a zero calorie Powerade. It does contain "fake" sugar, which isnt very good for you, but it also has all the good for you vitamin and mineral electrolytes - a bonus! Especially if you are exercising. :) Lots of flavors.
You could try adding to the water lemon and mint are my fave also try some of the drops they have to flavor water alot are low to no cal most are sugar free.
You could drink green tea. With a low calorie sweetener