Via Kitchen Monki
Add both ingredients to a cup, plus an ice cube or two, and garnish with fresh berries, mint or lime. It’s best to make in small batches as the club soda quickly loses it’s carbonation.
(I don’t add sweetener to mine, but you can also add the sweetener of your choice! I prefer light tasting sodas: watermelon is my favorite and I like to leave it in chunks :).