Steep the nilgiri and assam tea in 2 cups of hot water for 10 minutes.
Add 3/4 cup raw cane sugar, maple syrup, or my personal favorite, coconut sugar, and stir well.
Stir in mint extract or other flavor options, if you'd like, and add 6 cups ice cold water.
Notes
If you'd like to make a bulk batch, just mix 1 cup nilgiri and 3 cups assam and store in an airtight glass jar. Steep 1 1/2 TB of your blend in a few cups of hot water and add enough cold water to fill a 3-quart pitcher.
If you'd like to make a no-calorie option, steep 1/2-1 tsp of stevia leaves with your tea blend and there's no need to add any other sweetener.
To save the most money, buy these teas in bulk (I will order 1 1-pound bag of nilgiri and 3 1-pound bags of assam when I order) and store the extra in an air-tight container in a cool dark place until ready to use.