This is the first chai recipe I developed years ago using a few different ones, plus advice from servers at Indian restaurants. I wrote a little bit about this in a blog post.

Make the masala:

3 inch cinnamon stick
5 black peppercorns
6 cloves
6-8 cardamom pods with shell (or about 3/4 teaspoon ground cardamom)
1 teaspoon ginger powder
some fennel seed

Grind the spices together in a spice/coffee grinder or a mortar and pestle.

To make one cup of tea:

Put 1 cup of water in pan.
Add 1 teaspoon sugar, 1 teaspoon tea and 1/4 teaspoon masala (the spice mix).
Bring it to a boil and simmer 1 minute.
Add 1/4 cup milk.
Bring back to a boil and simmer 3-5 minutes.
Strain tea. 
Enjoy … and adapt it to your taste!