Do you use one of those little mesh ball thingies + loose tea?
I use a few different things for brewing teas. I occasionally use a mesh ball for single cups. You can get fill your own paper teas bags. I use those more often because they allow the leaves to expand more than an overpacked tea ball. You can get those at tea shops like Teaism, Teavana, World Market, and maybe elsewhere.
For a single cup, I prefer to use either a mesh basket so the leaves can float, expand, etc... The traditional way would be to put loose leaves in the teapot, then strain them as you pour either into cups or into a second tea pot. I'm sure that's Old Chelsea's way.
I have a neat sort of reverse french press, too, that you can get from Teavana. basically, you put your leaves into the device, pour in the hot water, and, when it is ready, put the thing on top of your cup. The way it is built, the edges of the cup will press up a plate that opens a drain at the bottom that lets out the tea. The advantage this has over a french press is you don't get a bitter squeeze of the dregs at the end. Bodum or Bon Jour is the product line.
I mentioned that I prefer a mesh basket. It's a nice compromise between brewing in a pot and the convenience of having the leaves set aside. There is a line of cups and tea pots with fitted baskets called "For Life" that I like. You can also find mesh baskets sold on their own that you can use with any cup.