It may be too late to ask for old wrapping paper, but I thought that I'd throw it out there! Used, crumpled -- it's okay! Especially the metallic or foil kind that you can't put in the recycling!
Old holiday cards -- feel free to tear the sentiment side off -- or leave it.
White, clear or silvery "little stuff". It needs to fit in a jar..... Think little bits of yarn, glitter, sequins, broken jewelry, ribbon (used curly ribbon is great). We will need this asap.