First, next to the ingredients, prepare a jug for the iced tea. Fill the jug 2/3 full with ice cubes and squeeze the juice of half a lemon.
In the meantime, steep two bags of black tea in a cup of boiling water (I personally recommend Earl Gray and let it steep for about 5 minutes). Then empty the cup of tea into the jug with ice cubes. This prevents bitter substances from developing. Now cut the remaining half lemon and, if necessary, another one into slices and add to the drink.
Add a dash of elderflower syrup and mint to the drink if you like. Fill the jug a little with cold water, mix everything and cool in the refrigerator.