People say many great things about Kombucha. I don't know what of it is true, but I know that I surely enjoy fermented drinks such as Kombucha or Water Kefir. It's a great alternative to sugary drinks and saves packaging and transportation.
To make Kombucha, you need a Scoby. If you ask me, it looks similar to a ... well, never mind, it's a magical living being that transforms sugar into taste, while making it a treat for our gut. Where to get a scoby? Ask around, post in local groups.. someone will have some to share!
Once you have the scoby, you will receive it in a bit of kombucha (the scoby must never be dry!). Put it in a big jar, ca 3l.
Make 2l of black tea with 1/2 cup of sugar. Let it cool down until the tea has room temperature (important!) and add it to the scoby in the jar and cover it with a towel. Keep it anywhere at room temperature. After 4-5 days the new kombucha is ready. Fill the kombucha into bottles and remember to always keep the scoby covered in kombucha. Now you can make new tea again, and in 4 days you'll have the next batch. Enjoy!
*** You can add flavours in the so called "bottle fermentation" (aka after you've filled it in a bottle) such as orange, berries, cinnamon, ginger... play around! The internet will also give you ideas :)