I have made several tasty and refreshing iced teas by simply taking a single quality loose tea, steeping and then if you like, flavor with lemon, lime or both. Add sugar or honey to taste and pour over ice.
A great way to prepare your tea is to take a half gallon pitcher, fill with water, add 7 or 8 rounded teaspoons of tea and steep in the fridge over night. Cold steeping like this makes for a milder, naturally sweeter brew. Pour through a fine strainer over ice and enjoy.