This project could not be simpler or more beautiful.
1. Lay your hands on some vintage costume jewelry. Check thrift shops, estate sales, or your grandma's jewelry box.
2. Get some ornament hooks and simply find the most logical hole in the jewelry piece to put it through. Clip-on earrings are especially good (because the clips always have tiny holes). Pendants and pins are also great.
3. Hang on your tree.