1. Adjust the arrangement of candy: rearrange the position of candy to fill the box more tightly. Try placing the candy vertically, or fill the gap with some props, such as colored paper, ribbons or paper towels.

2. Add fillers: put some fillers on the bottom or side of the box, such as colored paper, petals, candy paper, etc. Increase the fullness of the box, which can not only fill the gap, but also increase the decorative effect.