To create a new geofence, click Tools->Geofencing->Add geofence. Type in geofence name and select it's color, then click on the map to begin drawing geofence. When you finish drawing geofence, duoble click the last point and click Save.
Once geofence is created you can view them all on the list and edit anytime.
Also you can export or import geofences. It is possible to import .KML files also.