When taking pictures, you should look up and take a deep breath, put your tongue against your palate, look natural, "think of good things in your heart" and smile slightly; Meditate on "eggplant" or "Tianqi". In addition, if the customer has a double chin, pay attention to it: lower your head and lean your head forward a little, so there will be no double chin when taking pictures.
In addition, you need to pay attention to clothes and hairstyles. It is best not to wear clothes with the same color or imitation color as the background color. It is best not to wear hats and down jackets in winter, and it is best not to wear scarves and large fur collars. It is best not to wear shoulder vests (hurdles or suspenders) in summer, and it is not good to have a low chest. It is best to choose T-shirts with leaders printed on them, or shirts such as suits, ties and jackets. You can ps a little if necessary.
I hope it will help you. Take a satisfactory certificate one day.