My favorite fabrics to stock up on when I can are tone on tone fabrics, mostly white and beige, but other colors as well. I think the tone on tone used as a background makes for a more interesting quilt. If it's a great sale, I'll try to pick up some fabrics I can use for backings of my quilts, especially since I make mostly bed size quilts. But if a fabric just happens to fall into my cart, telling me to take them home with me, I usually do. LOL.