Hi Blue Ciel
The ground rod is the best way to go. We prefer going directly to Mother Earth. But if you are above the second story it gets a little complicated (you need an extension or two). If your electrical outlets are properly grounded you should be fine. Just insert the Earthing cord prong end into the ground port (third hole) of the electrical outlet and snap the other end onto your Earthing system (sheet or mat). Happy Earthing.
Martin Zucker, coauthor of the Earthing book