1. Starting in the middle, place first washi tape strip across the disc. Then work down on one side by continuing to add more strips. Then continue in the other direction until the entire disk is covered. Make sure the strips are perfectly next to each other without overlapping. It does not matter if strips are hanging over the edge. These will get cut away anyway.
2. When finished, your disc now looks like this.
3. Turn the disk over. Cut along the rim of the disk and trim away the excess tape.
4. Now it looks like this. Add a string through the hole for hanging when finished.