Principle 1: Good tea comes from good tea leaves.
Asian teas are loose-leaf, not in bags like in Europe or America. Before steeping, the leaves are scrunched into little pebble shapes from drying, but once hot water is added, they expand into their original form. High quality teas will be bunches of three well-shaped, un-torn leaves. Pairs or single leaves with maybe a few imperfections make up a middle tier. Substandard leaves are ground into tiny bits for use in tea bags. (Nowadays some luxury teas are sold in bags for convenience, but generally drinking tea brewed from a bag means you are drinking crappy tea.)
Principle 2: Tea flavor is proportional to proper brewing.
My next post will be about the Japanese tea ceremony, but the Chinese have a ritual too. After tea is added to a pot, near-boiling water- too hot water will scorch the leaves, damaging the flavor- is poured over the leaves, then immediately poured out over the tea cups. This first douse cleans and opens the tea leaves, then warms the tea cups; it’s not meant for drinking. Next the tea is steeped with a second infusion of water, then poured into warmed cups for imbibing. Asian tea cups don’t have handles; you know that tea is the correct temperature when you can pick up the cup without burning yourself.