I find that if you are making iced tea via the hot steep then pour on ice method, it is useful to add extra leaf to the tea. This invariably makes a stronger brew, but when you dilute it with the ice you end up getting a tea of the concentration that you normally like. I have also seen it suggested that you steep for longer, but in my experience changing the steep time changes the flavor too much, so I prefer to go with the regular steeping time.
Another method of iced tea brewing that I have been experimenting with recently is iced brewing. From where I originally heard this from, this method is ONLY supposed to be used for brewing a gyokuro. You fill your brewing vessel with the normal amount of leaves (the suggested vessel was a kyusu) and then fill the vessel with ice cubes. Let it sit until just after all of the ice cubes have melted, and then pour out your tea and enjoy. An important note on that is you want to make sure you get every last drop out of the leaves since a lot of flavor is held in each drop when brewing with this method.