With teabags, the bigger the better

A guide to drinking tea English style - Tea Tuesdays: The Chemis-Tea Of Pouring The Perfect English-Style Cuppa - has this tip about tea bags:

If it's bagged, make sure it's big. According to research by physical chemist Deo Jaganyi at the University of Kwazulu-Natal in South Africa, the shape of the bag doesn't matter, but larger bags will allow more flavor from the tea to infuse the water.

In particular, he says, those pyramid-shaped bags aren't any better than your average rectangle. "The shape of the pyramidal tea bag alone cannot increase the rate of infusion," he and his coauthor wrote in a 2001 study in the journal Food Chemistry.

And another tip.

If it's a very thick cup, a ceramic cup, you're going to cool down the tea very fast," says Miodownik. 

When tea first made its way from China to England, it was accompanied by very fine porcelain, which didn't bleed the heat away so quickly, he says. A thick mug might feel nice in your hands, but the thinner the cup, the longer the tea will stay hot.