What about the green wire from the ballast, the one that has a U shaped piece of metal at the end? I put all the greens together and clamped the U under a screw that holds the ballast to a piece of plywood. The whole thing (ballast, and the wood it's mounted on) sits inside a metal box with the ballast in contact with the box to draw extra heat out. Not sure if the whole thing's good or not.
Thanks,
Ken