I learned pretty quickly that having the top done right is essential to stabilty. Otherwise you end up on the ground rather unceremoniously.
I also learned that one should not make last-minute adjustments in the dark before going to bed, and that it is especially difficult to right the hammock from the inside after you've zipped up the bug netting.
What I have done so far is to make spreader bars for both the top and bottom out of fiberglass poles from an old tent. They were sized perfectly and are quite light. The spreader bars increase the comfort and give me a nice "box" to lay in where I can listen to the mosquitos buzzing hungrily a few inches from my face.
The drawback to the top spreader bars is that it makes it difficult to hang the rain fly close to the tent without it touching the spreader bars.
So the setup is a lot of "fidding." First hang the hammock, then raise the top and tie off 6 guy lines (3 on each side). Make sure it's stable, then run a ridge line for the rain fly and tie that off. When we went scout camping my son had his tent set up and done while I was still fiddling with the top lines.
Plus, the thing is a beast and the canvas bottom seems to really suck up the humidity.
BUT--it still beats sleeping on the ground. I can get up in the morning and actually move.
I like the feel of this setup versus the "wrap" feel of setups like a Hennessey. Someone suggested a bridge hammock and that seems to address a lot of my setup problems by having a single top line to set up.
I'll keep experimenting.