I went out and hung my hammock the other day to determine the exact size of the bug net I will need. I want to keep it as small and lightweight as possible. I arrived at a bug tube circumference of 200 cm (6.5 feet) as optimal for my needs, and the length of the net would need to be slightly longer than the length of my hammock fabric, so 10 feet long.
Rather than sewing a tube out of a rectangular 6.5' x 10' piece of bug netting, I can taper the foot end of the net and save some weight. After all, I only need to enter through one end of the net. The other end can have a 2'' diameter opening, and that will be enough to slip it over the end of the hammock.
I have to keep in mind that I will probably occasionally be sleeping on the ground in this netting as well, so it has to be usable for that as well.
I have decided to put a side zip on the bug net. I've reviewed the experience of other hammock campers who've sewn similar nets, and I think a 4' to 6' long side zipper will make it a lot easier to get in and out of the bug net. Also, I won't ever have to take it off the hammock when packing up, unless I spend the night on the ground.
Now, if I'm always using the side zip, then I might as well taper the head end of the net as well, right? Or am I going to want to leave that end open so that I can pull the netting over my head in a standing position? :)
Final question. It might be a good idea to sew the bottom half of the bug net with windproof lightweight fabric such as Momentum or standard 1.1 oz nylon. This way, the hammock body is protected from wind as well as bugs. If it is hot and the wind is welcome, the bug net could be rotated to have all netting on the windward side of the hammock. However, I've decided against this option for simplicity's sake. I'm unsure of how it'll work in practice, and I only have one shot to sew the bug net.
I just ordered all the necessary materials from thru-hiker.com: 5 yards of 60'' wide noseeum, an ultralight continuous coil zipper with 2 double-pull zipper sliders, some draw cord and cord locks, and hydrophobe sewing thread for this and other sewing projects.
I decided to stick with the tube shape and not taper anything, because that would make it significantly harder to sew. The net has a long 7' zipper along the side that can be shifted under or over the hammock as necessary. Thanks to my mom for a fine sewing job.