I also love True Lemon and True Lime, because unsweetened drinks seem more refreshing. An easier-to-find (but less natural) alternative would be to use a dash of unsweetened Ice Blue Raspberry Lemonade Kool-Aid in water -- barely enough to give it a pale tint.
And, although tea doesn't interest you, consider letting a peppermint tea bag rest in a glass of ice water. It creates a subtle minty flavor.
Goal: To eat mindfully, move joyfully, and live as a radiant round woman