Very simple. Take a jug of water, about 1 liter, throw in two boxes (like the plastic containers the berries are sold in) of frozen berries (blueberry, strawberry, raspberry, blackberry), one small cucumber (peeled into strips), one lemon (cut into slices), a bit of mint if you like. Let it sit in the fridge for at least 30 min, enjoy. The frozen berries are like yummy edible icecubes keeping the water nice and cold. Cucumber and lemon give you a burst of freshness. Or you could do what I did today and throw a few frozen berries into a glass, fill with water, enjoy.