I've tied thread necks with a long thread section and a short one, just to see if it made a difference. The longer bodies (about 1/4") worked better on the days I tried em. The amount of hair is something I haven't fooled with yet, so this is good info. Like most folks I probably use more than needed. I also have some red angel hair that is going into my next ones. Just a hint of flash and color. I looked at the store bought ones the other day and the eye is very big, almost the whole head. I also noticed that they don't come big, 1/16 is as big as they get, but they go real small. Most of these had black heads and white/black eyes. These were definitely tied on ball head jigs.