Most people look at me like a crazy person when I ask them if they would like some Kombucha, but it's becoming quite the popular drink. I personally make my own Kombucha every week and I'm currently experimenting on flavoring it different ways. The steps to make it is super easy, if you already have a SCOBY (Symbiotic Colony of Bacteria and Yeast). Instead of re-creating the wheel, here are some great visual steps and informational posts from Tremendousness
An interesting tool we have, since our home isn't quite climate controlled, is this nifty little insulated box that Jake made. Originally, the idea was for making cheese so it can set in a climate controlled area. For now, I use it to let the Kombucha ferment almost perfectly with a heating pad that we set between 70-75 degrees.