There is a myth being circulated by some marketers of tea that large leaf teas are always better than small leaf tea. This is not so.
The truth is that there are some teas, particularly those which are strong and aromatic, that are enjoyed better as a small leaf size (or to use the terminology of the tea trade, a broken grade).
This is particularly true of teas to which milk is generally added.
After tea is processed it is separated into leaf size by vibrating sieves, so larger leaf sizes and smaller leaf sizes are produced by the same process and at the same time.
What is true is that the larger leaf teas are more subtle, not stronger or better, than smaller leaf teas.
As a general rule the smaller the leaf size, the stronger and quicker the infusion.
While the ideal water temperature for different types of tea varies, the practical reality is that in everyday situations such a level of perfection may be hard to achieve.
However, as general rule, whatever the tea being infused, the temperature should never be more than the immediate point of boiling (approx. 95C).
Water temperature that is higher than this will scald the leaves, destroy the aroma and the tea will taste bitter. So do not overboil the water.
Conversely if the water is not hot enough it will prevent the leaves from releasing their full flavour.
Green and white teas are best infused with water that is just before the point of boiling.
Water quality is a major contributor to an enjoyable cup of tea.
The water should be clear and free of any sediment and minerals. It also should be freshly drawn because the oxygen content of fresh and running water is high and contributes to the enhancement of tea quality.
Unfortunately a lot of tap water has minerals and additives so filtered water (never distilled) is best.
The kettle for boiling the water should be emptied after use as stale or reheated water will diminish the quality of the pleasing cup.