To create a new dock, simply select an item from the "New Dock " submenu in the File menu. This will create an empty dock and open up its Dock Options window so you can change the name and any other settings you may wish to change.
You can add your own stationery to this submenu by saving a copy of a dock into DragThing's Stationery folder.
To show the Process, Disk and Window docks, select them from the Window menu or check the appropriate option in the Docks section of the Preferences window.