In connecting the rings to the hammock - I suggest the following:
wrap the cord from the hammock around the rings at least twice, preferably 3 times then tie a bowline with a single or double overhand safety knot.
http://www.animatedknots.com/bowline...matedknots.com
The larks head works okay for very flexible cord such as the BPL aircore, but with stiff cord such as the HH cord, the larks head tends to separate the rings which often leads to the webbing slipping - at least for me it does. I have used the wrapping and bowline now on very stiff cord up to 1/4" diameter with no slipping whatsoever. Wrapping the cord around the rings keeps the rings held firmly together.