Specifically I've been trying to add some condensed milk to Chai, but it seems no matter what I do all I get is the same flavor in slightly differently-colored water as before. Basic procedure I've been using is to steep the tea and then add said condensed milk out of the can immediately before serving—not certain on the total amount, but probably about 2 teaspoons, perhaps? Any suggestions on how to get the flavors to blend?
Have you tried steeping the tea in the milk? Whenever I make milk tea, I always do a 3/5th cup of whole milk, 1/5th cup of condensed milk (for sweetness) and 1/5th cup of water. I then bring the mixture of milks and water up to about 140F and steep my green tea and spices in it. This gives me a nice thick latte-like consistency and strong milk taste without overwhelming the tea and chai spices.
If you want more milk flavor, add more condensed milk. Milk has a very subtle flavor, so even with condensed milk, two teaspoons really isn't very much.
If by the time you get enough of that in, the tea flavor is too diluted, make tea concentrate the next time - steep the tea in less water.