In an ideal world you have to forget the notion of teabags. Nowadays the tea used in bags is infinitely better than the tea dust that was swept off the factory floor and used. However, only resort to a teabag when all else fails.
The world of teas is vast and wide these days. There's China, India, Ceylon, African, Blended, Fruit, Herb and Spiced. Everybody discovers favorites they enjoy depending on their mood and the time of day.
Look for established brands of tea which will guarantee quality and give you a yardstick by which to judge flavor by. A good British brand would be a company like Twinings. Some teas you might try for the afternoon are Ceylon, Earl Grey, Darjeeling and, if you really want to push the flavor boat out, try Lapsang Souchong. Ceylon is a light, golden-colored tea with a soft, round flavor. Darjeeling is very much darker and slightly sharper.
Earl Grey blends Chinese tea with citrus oil of bergamot. Legend has it that the second Earl Grey, a former prime minister of England, was presented with the recipe by an envoy on his return from China. This tea is very refreshing with a citrus tang. Finally, Lapsang Souchong is a large leaf China tea that is smoked in large baskets over oak chips. As you might expect, this has a very distinctive smoky flavor and, as such, is an acquired taste, but certainly worth such effort.
All of these teas can be drunk black or with milk and sugar. The milk should always go in the cup first. The essentials for a good cup of tea are, first, a clean china teapot. China pots seem to make a better cup of tea and they look the part. Swirl a little hot water around the pot to warm it. Next boil fresh water. Don't overboil as this destroys the oxygen in the water and makes the tea taste flat and dull. As the water boils, empty the teapot and put in a teaspoon of tea for each person and one for the pot. As soon as the water's ready, pour onto the tea and brew. This will take about 3 minutes for small leaf teas and and 5 to 7 for larger leaves. Stir once and serve.
Be sure not to serve tea that's brewed for too long as it will taste stewed and bitter. That's the signal for another pot. When you get to that point you're well on your way to becoming a tea addict and you'll find recharging your batteries English style with tea and scones will soon become an absorbing habit.