I have eight lines approximately five feet in length for my GoLite Poncho/Tarp. There is a bowline and a ZPacks mini-biner on one end and a tautline hitch on the other end.
I am toying around with putting triangular linelocks on the lines. In the morning, I fold each line in quarters and tie a slipped overhand over the folds. Each line is stored unconnected to the other. To set the tarp up, I attach the 'biner, the pull out the slipped overhand and stake as necessary.
I like having the tautlines because it allows tension without noticeable weight gain. I can also tie a clove hitch (tied using loops) a la Ray Jardine.
If I was using a small non-poncho'd tarp, I would use shorter lines, especially on the side guys - perhaps around three feet.