Heat the water until it reaches a boil. You can do this in a kettle or on the stove.
Once the water is boiling, pour it over the tea bags in a large pitcher. Let the tea bags steep for about 5-10 minutes, depending on how strong you like your tea. For a stronger tea, steep longer; for a milder flavor, steep for less time.
After steeping, remove the tea bags from the pitcher. Be careful not to squeeze them as this can release bitter tannins.
If you're adding sweetener, do it while the tea is still warm so it dissolves easily. Adjust the amount of sweetener to your taste.
Allow the tea to come to room temperature. You can speed up this process by placing the pitcher in the refrigerator.
Fill glasses with ice cubes. Pour the cooled tea over the ice, garnish with lemon slices, mint leaves, or pieces of fresh fruit if desired.
Notes
Over-steeping can make your iced tea bitter. Refer to the specific tea's recommended steep time, and reduce it by a minute or two for iced tea.
Let the tea bags drip naturally. Squeezing them releases a bitter flavor.
To sweeten the iced tea, start with ½ cup of sugar and add more if needed.