You could also use a length of medical tubing to run your tarp line through and around the tree to pad the line. I've seen people do that before as well.

Another option is to make a rain fly for your hammock which sits directly over you hammock ridgeline and truly makes you hammock a suspended tent. Can't move around in the rain as much though, so probably only for the SULers and mega-milers who only hang long enough to sleep.