How is British tea prepared?
The British tea? Don't know what that's all about. Anyway...

English Breakfast Tea is a mixture of Assam, Ceylon and Kenya teas that is often served with a dash of milk and sugar to taste. The UK Tea Council discusses their view of the appropriate way to serve each variety at the supplied link. I would think that a great majority of British people take their tea with milk (I don't find the type of tea used palatable without, as it is somewhat bitter and high in tannins, and I don't think many other people do either). When I say a dash, what I mean is somewhere in the region of 10% of the volume of the cup, rather than the half and half or thereabouts used in beverages like chai.

Most British people (in my experience at least) use teabags which are simply added to the cup and hot water poured on top. However adding several spoonfuls of loose tea to a teapot is not uncommon, as was probably done for millennia wherever tea was drunk, prior to the invention of the teabag.