I'm too cheap to buy an underquilt, and doubt I'll do much winter hammocking, so the ZHammock became the wise choice for me to build, as I already have a foam pad, and I don't want to lay directly on the pad, but shove it between the layers. I did run into some problems when constructing a ZHammock, and made some modifications. The main problem during construction is the difficulty in getting two pieces of material cut to exactly the same length (I don't have a large empty area to do my work), If they're not the same length, when you sew them together, this can be a problem. This method allows you to do a rough cut and trim the excess off later.
Also, anytime I plan on going camping, there are going to be bugs, so for simplicity, and because I'm cheap, I'm sewing the bug net directly onto the hammock. The location of the bugnet also allows it to be stowed away in the 'pocket' of the hammock, or flopped into the hammock when loading it up with a pad. When whipping, I plan on embedding a loop of cord through the whipping so that I can attach a non structural ridgeline with a tautline hitch to tighten it up.
Click on picture for details.