I haven't really made chai with the regularity of which I did back in the hellhole, but I do still remember!
After looking up recipes, and trying stuff out, a mix of 50/50 water and milk seems to work best.
Bring the water to a boil, then add: milk, black tea, and spices (cinnamon, cardamom, cloves, allspice, etc.). Simmer for 5-10 minutes, or until the color that you'd like. Serve hot.
I like to make a big ol' pot of this, and just keep reheating it on the stove for each mug. It's so nice and comforting; and now that I have to be frugal, it keeps me from going to cafes as much. :-P