You wouldn't really be "brewing" it in the sense of making beer. Just get some tea and your favorite liquor. Or experiment with different ones and see what you like..
Its pretty decent. I bought a bottle and typically mixed it with water over ice. Add a splash of lemon and a tiny bit of powdered sugar for that real southern sweet tea taste. Or you can just add it straight to sweet tea.
Whiskey + tea = absolutely amazing. If you mix in the right ratios, it tastes like burnt honey. Red Diamond sweet tea and Wild Turkey 101 are the best combo, IMO.