Those bottle flavored waters are nice once in awhile. But they are pricey if you drink them daily. As well you can't control the sweetener, if any, that is used. So I make my own version. The base is plain water--usually reverse osmosis water which I purchase by the gallon for $.34 (refill price). If I want a fizzy water I buy carbonated water. Keep a container of water or a bottle of fizzy water in the fridge so it's good and cold when you want it..no ice needed. (For drinking plain water I prefer it at room temperature.)
To the carbonated water I like to add a small amount of fruit juice--maybe a couple of tablespoons to 8 ounces of water. It makes a nice slightly sweetened fizzy drink. Not too sweet and not too calorie dense.
To the plain water I like to add a tiny amount of unsweetened Kool Aid powder--kiwi watermelon is my favorite. I don't measure, I just sprinkle some in. You want just enough to flavor the water but not so much it makes it too tart. Generally I don't add any sweetener to it. I find that sweetener--real or artificial-- makes me crave more sweet foods or food in general.
For the price of a 20 cent pack of plain Kool Aid and a refill gallon of water for 34 cents you can have a whole gallon of flavored water. It tastes just as good as those single serve bottles for a lot less money. If you want to take it with you, save or buy a portable individual water bottle. I saved a Propel bottle a long time ago. The plastic from that brand is very sturdy and easy to wash and reuse.
You can flavor water too with thinly sliced fruits or vegetables. Cucumber is nice. So is lemon, lime, or orange. I like to put my water in a nice goblet and add the sliced produce. It is a pretty presentation. I find making things fun causes me to tend to do them. I keep a special glass too, just for drinking my water at home. As a rule I fail to intake enough liquids during the day, often waiting until I'm thirsty to drink. Making drinking water special causes me to drink more of it.