I use a quilt too, whether on the ground or in the hammock. I have 2 DIY quilts.
I made one quilt out of a $40 down comforter, simply sewed to enclose one end of the comforter for the footbox. This packs down to a size of a large grapefruit.
I also made another quilt from an old mummy bag. I cut out all the zippers and the hood, plus got rid of other excess material. It weighs about half original weight and packs down to half the volume.