In use, the Bug Cage covers me to the hips. My sleeping bag protects my legs. There is a foot of material around the lower edge that can be tucked under my ground cloth, and the foot-end has enough extra material so it lies loosely across the sleeping bag at my hips.
Use black netting. It's easier to see through.
Cut out the pieces to make the Bug Cage using the pattern shown below. Five yards of netting, six feet wide, is enough to make the cage with enough left over to make a head-net or two. Use ½-inch edging tape on all edges and seams when joining the pieces together. Add loops of the edging tape at all four corners of the top of the cage so it will hang under the tarp from your hiking poles and tie back to your tent stakes without sagging.
The dimensions given here are correct if you are using my poncho/tarp-tent plans. (Click on Poncho Plans from my home page.) Otherwise, modify the size so your Bug Cage fits loosely under your shelter without sagging.