To make a good promotional film, we must grasp four problems. First, fully publicize your purpose and central idea, let everyone know what you are promoting, and be sure to fully express your shooting purpose; The second is to write a script. This work is hopeless. Some people shoot and write in order to hurry. This method is wrong. The third is to raise props and costumes around the script and get everything ready; The fourth is to shoot with suitable equipment. I hope this answer can help you.