Using a paintbrush, apply acrylic paint to both halves (inside and out) of a pressed-paper ornament box (pinecone or acorn). Let dry.
With another brush, apply size (an adhesive available at art-supply stores) to front of ornament (cover the lip that runs inside 1 half ). Let size set until it becomes tacky, about 20 minutes.
Wearing cotton gloves, lift 1 gold- or silver-leaf sheet. Drape over front of ornament; smooth gently with fingers. Using a soft-bristle brush, even out texture, removing stray flakes. Repeat, overlapping sheets slightly, until front is covered.
Reapply size and leaf to sections that aren't fully covered as directed in steps 2 and 3.
Fill half of box with shredded glassine and cookies; close box.
Size (adhesive available at craft and art supply stores)