Let's start with something super easy. I bought a bag of these little red, glittery "balls" at the Dollarama. They kind of reminded me of holly berries at the time (who knows why... maybe I'm just crazy). So I tied some green ribbon through one of the holes to make a loop. Then I tied some shorter strands of green wrapping ribbon around the other ribbon near the ornament. using the edge of your scissors, curl the ribbon.
And done. Nothing extremely elegant, but at least it is an ornament and will brighten up a tree.