Dress in one solid colour, white would work well, however you might consider black. Make sure your shirt has a color. Wear the collar "up".
You may be able to find a large "ring" at a novelty store. If not, be creative and make your own. You could use a quilters hoop, you can purchase at a craft store fairly cheap. Also pick up some craft or floral foam to carve out a "diamond".
Wrap the quilters hoop in gold tissue, gold wrapping paper or aluminum foil if you cannot find gold. If you think the hoop is too thin, pad the ring first with newspaper or other scrap paper and then wrap with your gold covering.
Have an adult carve out a diamond (the stone) shape in the craft/floral foam. Attach to the quilters hoop with wire, or feed the hoop through the foam. You may have to carve out a tunnel in the foam first.
Wrap your diamond shape foam in either aluminum foil, or plastic wrap to make it look like a dianmond stone. If your foam is colored, not white, first wrap in waxed paper, or other white material to conceal the colour of the foam. Using plastic wrap will give the diamond a sparkly look. You could attach glitter to the diamond with a spray adhesive.
Once complete, hang the finished ring around your neck. You are now "Ring Around the starkly"!
Thanks to Wendy for this idea.