Bring 2 cups (480 ml) water to a near boil in a saucepan or kettle.
Remove from heat and add tea bags or loose tea in an infuser.
Steep the tea for 4–6 minutes for strong flavor; adjust time to taste.
Remove tea bags or strain leaves, pressing gently to extract flavor.
Stir in sugar or honey while the tea is warm until dissolved, if sweetening.
Pour the concentrated tea into a large pitcher and add the remaining 6 cups cold water.
Add lemon slices and stir to combine.
Chill the pitcher in the refrigerator for at least 30 minutes or until cold.
Fill serving glasses with ice cubes and pour chilled tea over ice.
Garnish with lemon wedges and mint sprigs, then serve immediately.