1. Fill the kettle with fresh water from the tap. Yes, your grandmother was right: water that has been boiled already will affect the taste of the tea.
2. As it approaches the boil, warm the teapot by rinsing it out with hot water.
3. Treat the teapot to one rounded teaspoon (yes, or caddy spoon) of tea leaves for each person and one extra spoonful 'for the pot'. That’s the orthodox rule, though many these days find it a little strong. You’re in charge here.
4. Leave to infuse for three to five minutes, depending on taste. Serve, using a tea strainer.
5. If making tea in a cup with a tea infuser, the same rule applies – one spoon of tea, use water just off the boil and infuse for 3-5 minutes.
From Fortnum & Mason