Bone paper folders are a traditional Japanese paper crafting tool used to fold origami and other paper crafts. To use a bone paper folder, follow these steps:

1. Start with a square piece of paper.
2. Place the paper on a flat surface with one of the corners facing you.
3. Hold the bone paper folder with the flat side against the paper and the pointed end facing away from you.
4. Use the flat side of the bone paper folder to gently crease the paper along the edge of the tool.
5. Repeat the creasing process along the other edges of the paper to create a series of parallel lines.
6. Use the pointed end of the bone paper folder to make sharper creases in the paper.
7. Fold the paper along the creased lines to create your desired shape.