I’ve been making masala chai at home for the past few months. Since I also favor a spicy chai, I start by throwing lots of fresh ginger, smashed with a mortar and pestle, into the boiling water with my spice mix. I let it boil for a couple of minutes, then add CTC (crush, tear, curl - the tea looks like little pebbles) assam. After another minute or so, I add whole milk and sugar. At this point, I watch it like a hawk since it can boil over rapidly. Two people taught me how to make chai masala: the first person told me to let the milk almost boil over twice before calling the tea done, and the other person told me to let the milk almost boil over 5 times. I average it out and do it 3 times. 
I’ve experimented with whole leaf assam, but I found the taste different from what I had in India. The chai wallah I watched make tea in Delhi used the CTC assam, which I found at an Indian grocery store for a fraction of the price I was paying for the organic whole leaf assam. I want to find some organic CTC assam, and may have to resort to buying it online if I can’t find it at the Indian markets near me.
My spice mix has loads of cardamon, black pepper, cinnamon, and a small bit of cloves and nutmeg. When I have time, I toast the whole spices before crushing them in the mortar and pestle. I make enough for masala for about 5 servings, and any unused portion goes into an airtight container.
