1. First tie the two straps at the back of the hat irregularly behind the ear, with the height between the eyebrows and the earlobe.
2. Then tie the two straps in front of the hat irregularly on the back of the head, which are also located between the earlobe and the eyebrows.
3. Finally, adjust the position so that the left side of the hat is parallel to the ground and the hat is facing down.
The doctor's hat of Birmingham University is a square "Oxford hat", and a beautiful tassel hangs on the left side of the hat. The color of the tassel indicates the department where the degree is awarded.