Yeah, it doesn't require anything additional. The way it works is to pull the pin hard to ground using the output transistor on the pin. Then it starts timing how long it takes for that pin to register as a high input value after a built-in pullup resistor is turned on. Since that resistor has to charge whatever capacitance it sees on the end of the wire, the timer value is a good proxy for capacitance. There are lots of articles about how to design the layout of the conductor you connect according to what you want to do - keyboards, sliders etc. I often run ground traces between and under capsense traces to better isolate or control sensitivity.
I have conductive silver pens, conductive fabric and conductive copper tape on hand to quickly experiment before committing to a PCB.
Alice made an inspiring art piece using scraps of conductive fabric and the library:
http://www.adrianfreed.com/content/...fast-portable-low-fidelity-capacitive-sensing