The most common way to make iced tea is as follows:
Put double the amount of tea leaves you normally use in the infuser (So for example, for a 2 cup infuser, instead of putting in 2 tsps of a green tea, you would put in 4).
Next, steep as you normally would, in this case three minutes for the green tea.
Then dilute the tea by putting in an equal amount of cold water, in this case two cups. Then put in the refridgerator to enjoy at a later time!