A lot of the time the little boxes and bags that are too small for an actual gift box are perfect for packing a box and separating smaller kinds of cookies. From festive plastic bags to tiny treat boxes - you'd be surprised at what you can get at the dollar store. You can also use holiday ziploc bags, plastic wrap, and cellophane to separate cookies. Foil tins, small cookie tins, cupcake liners, mini loaf pans, or even cardboard ornament dividers are also great to create sections in your cookie boxes.