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.
Re: All Things Meditation
I've often made a nice bowl of matcha before doing zazen. (In a way, the meditation starts while I'm preparing the tea.) Not only can the tea making process be a nice and gentle start to your meditation, but the effect of the tea itself is of great help during the meditation - especially if it is in the early hours of the day, and you're like me not much of a morning person
Funny enough I started reading Shōbōgenzō the day this topic was started.

Funny enough I started reading Shōbōgenzō the day this topic was started.