Besides being very pretty, these golden walnuts were easy enough for my five year old son to create, and all the supplies (except the walnuts) were already sitting in my cupboard.
-- Gold acrylic paint (silver would be pretty, too)
-- Small screw-eye bolts like these
-- A paint brush
-- White (PVA) glue
-- Some ribbon and cord or string
STEP 1 :: Twist a screw-eye bolt into the top of each walnut. You should not need a drill because the area in the center, at the top of the walnut, is soft. Don't worry if the screw-eyes feel wobbly -- you can secure them with a drop of glue later, after you have applied paint.
STEP 2 :: Paint your walnut shells gold (or silver, or whatever metalic paint you happen to have stashed in the cupboard) and allow them to dry.
STEP 3 :: If the screw-eyes on your walnuts don't feel secure, add a few drops of white (PVA) glue at the bases of the eyelets, where they are bolted into the nutshells.