The Art of Tea's Steve Schwartz is very particular about how tea should be tasted.
"When you're evaluating a tea, take a look at the whole dried leaf, and once the tea is brewed, examine the wet leaf, notice the color of the infusion, and, of course, the taste," he says. It's important to pour the tea into a white cup. "You want to be able to see all the way down to the bottom. There should be depth and clarity behind the tea."
Tasting tea is similar to tasting wine in that you should slurp it.
"First, take a small sip to get a sense of the temperature and the flavor," Schwartz says. "Next, draw the liquid into the front of your mouth and swish it around. That helps aerate the tea and cool it. Then slurp it back so that the liquid covers all the taste buds, swallow and then, with your lips closed, take a slow breath out through your nose. Over 80% of what we taste is actually through our sense of smell, so this really engages the olfactory senses."
That last step, breathing out through your nose, is important. It seems to amplify the scent and flavor of the tea. One more note: The quality of the water really matters.