I have a king size bed that I cover with an old flannel flat sheet. The flannel keeps everything from moving around, better than clips or tape, and is large enough to cover everything and protect it from over spray. My batting goes down first then I arrange the backing on that, peel back half, spray lightly, and smooth down. Repeat for other half. Wait few minute (time for cup of tea?). Flip over so batting is on top and repeat process for quilt top. When spraying I direct the mist toward the center to cut down or eliminate overspray. With really big quilts I have to lift and shift somewhat but that is not a problem. My knees & back love this method. Do note that I said 'spray lightly'. Always easy to lift sides and shoot a bit more in if necessary. My machine and/or needles have NEVER gummed up! I like June Taylor, Dritz, or 505. Sullivans (pink can) is really sticky and smelly.