Over on the Hammock Camping yahoo web site, several guys recommended using a double sheet bend knot to tie off the hammock ends. I tried it and it's pretty darn good and versatile. This knot can replace the Risk knotted test hammock end, , the whipping method or zip ties.
There's how to tie:
Think of the hammock, after bunching, as the bigger line.
I like the double sheet bend best. There is a slip version which is even better, because you can undo it easily.
Seems to be no chance of slipping off, yet it unties easily. Refolding the ends until you get that perfect lie is now much easier for me.