Start with cold water, or use bottled water.
Measure into the teapot 1 tsp. of loose tea for every cup you plan to pour. Some tea drinkers, especially those who take milk with their tea, add an extra spoon for the pot. If you're using a mesh tea ball, don't fill it more than halfway, to allow for complete expansion of the tea leaves.
For black teas, bring the water to a full boil. Remove the tea kettle from the heat as soon as the water begins to boil. Boiling all the oxygen out of the water will flatten the tea's flavor.
For green teas, remove the tea kettle from the heat BEFORE the water begins boiling.
Fill the pot with the boiling water. Cover the teapot and leave the tea to brew. In general, black teas are best brewed for 4 to 5 minutes; green teas should brew for no more than 3 minutes.
When the tea is ready, pour and serve all the tea. Remove the infuser from the water so that it does not over brew. Tea tends to taste bitter if it gets overbrewed.
A good-quality tea can be infused three to five times. Just add more boiling water. Let it steep for a little more time with each brew.