Making cinnamon water requires just two ingredients but you have your choice of techniques. One method is to simply drop a cinnamon (or cassia) stick in a pitcher of water and chill overnight. The water will become infused with subtle flavor; however, it will lack the lovely blush color of the water shown above.
To coax out the color, simmer the cinnamon in a pot of water on the stove; a ratio of 1 cinnamon stick to 1 cup of water works well. (As a bonus, your kitchen will smell amazing!) Cool the liquid and use it as a concentrate to mix with cold water and ice. It's quite good with fizzy water, too.