I wanted to share that I made bedskirts a few years back for all my beds, and some for a fishing lodge in Alaska. I took an old sheet and cut it the size of the box spring. Then I measured the length from the top of the box spring to the floor. I made the skirt like a quilt, with a front, back and batting in between. I loaded it on my longarm and stitched out a pantograph. Bound it like a quilt on the bottom and attached it to the sheet on the top. I allowed a little extra on the corners and folded it under to make a pleat so it would drape flat. They work out great and you don't have the issues like there are with flimsy bedskirts, because of the batting.
That way you are free to make any size of quilt for the top you like!
