well this thread was very informative so i thought i would add my experience with center one self.
the art of brewing itself is a calming relaxing technique. i will refer you to a simple page on cermonial matcha http://www.yuuki-cha.com/matcha-green-tea-powder
some have found that the act of tea brewing and the focus allows a person to calm themselves. here is a simple wiki on it as well http://www.wikihow.com/Meditate-While-Drinking-Tea
for me i center myself during the cooling post infusion process while the tea cools. i like my tea cool/warm rather than at temp. i also enjoy the flavor and texture of the tea.