* insulation on the bottom. Put a blue foam ccf in. You will need something for temps under 60F. Foam will be worlds more comfy in a hammock than on the ground, I promise.
* sleep on the diagonal, not end to end. Hang with enough sag to get "flat" this way. A 30 degree angle for the suspension on each end is the usual; if the trees are further apart you will need to tie off higher to achieve this.
* to conform to LNT use tree straps. to avoid making forest rangers and park staff angry with you, use tree straps. to keep the wilderness hammock-able for all, use tree straps, not rope. Tie the rope off to the tree straps. Did I mention use tree straps? Cheap hammocks won't necessarily come with them. You can order poly webbing for minimal cost at strapworks.com. Nylon streeeeetches and keeps stretching, polypro will stretch initially and "settle."
* use the sleeping bag over you like a quilt, or get into it before you get into the hammock.
* do not hang from dead trees, or under trees with a lot of dead branches. The force exerted on the trees is much greater than your actual weight. Also, look down, too. I set up after dark in a patch of what turned out to be poison oak....
* for further hammock related questions, hammockforums.net is the repository of all things hammock.