I'd say that the correct way is to pour about half a cup of boiling water into the teapot. Then swill it round and empty it to warm the pot. Quickly, add one teaspoon of Ringtons tea per person plus one for the pot. Then enough boiling boiling water for the number of cups of tea. Leave to brew.
(image from Ringtons website)
But I can't be bothered with that so I stick a teabag in a mug of cold water. Then microwave it for 2 minutes. Though, usually, I drink black coffee.