1. First prepare the following materials: plastic fresh-keeping bag, clean water and leather shoes.

2. Then pour the clear water in the cup into a plastic fresh-keeping bag, as shown in the figure.

3. Then tie the fresh-keeping bag filled with water and put it in the leather shoes.

Then put the shoes in the refrigerator for a night before taking them out. At this time, the shoes will be stretched, because the water will become larger after freezing.

5. Finally, the shoes won't pinch your feet after you put them on, as shown in the figure.