Dolly, I used an old bottom sheet on the boxed springs. I made my skirt in 3 sections using velcro to attach them to the bottom sheet. Works great as I'm in the process of making a new boxed pleated skirt this time in lieu of a 3-layered gathered skirt.
Also, I placed my velcro on the top near the edge just enough inside so it doesn't show when you pull the sheets down for the night plus the added weight from the top mattress makes sure the skirt stays put.
Suz in Iowa