I like drinking the cans of unsweetened iced green tea you can get from Asian groceries and some Asian restaurants so I worked out how to make the same sort of thing at home.
It’s super easy. Just pop two green tea bags in a 1L jug and fill with cold water. (I use tap water, but you could use filtered water if you want. In London I would recommend filtered. :P) Cover with cling wrap, pop it in the fridge and leave to brew for 4-6 hours or overnight. After that, remove the tea bags, pour and enjoy!
It’s very refreshing, especially in the warmer months, and it’s a healthy way to rehydrate because it contains all the antioxidants of green tea without any kj/calories (if you’re worried about that sort of thing). I used to use “Yoko Japanese Style Green Tea Steamed Dry Sen Cha” but I’m sure any kind of green tea bags would do the trick. I tried it with Madame Flavour’s Green Jasmine and Pear a couple of times and that was lovely.
Someone has also recommended trying it with oolong which I must do one day.