I use the plunger thingy for tea that is already ground up as it brews pretty quickly anyway. It may have been made for coffee but it works all the same. If you have actual leaves you need to boil them in the water to get them to brew properly, in which case I would use a saucepan with a pouring spout on.
Althogh a more arduous method it's pretty simple to do
I have used this method to make stinging nettle tea.
Here is an interesting looking device I just Googled -
Mmm, I want a cup of tea now -
*puts kettle on*