A piece of hard paper and a colored pen.

Second, the steps:

1. Fold the square paper up and down;

2. Then fold the rectangle left and right and unfold it to leave a crease;

3. Then fold the left and right sides like the midline;

4. Then fold the two sides in half and pull them apart;

5, flattening and flattening, and then folding the lower half of the central square structure upwards;

6. Then fold the top, and then fold the left and right sides in half to the middle;

7. Fold down the rectangular structure with the middle folded up.