I am not a professional photographer. How can I take good photos for my clients? Please give me expert guidance.

1, you should know to adjust the posture of the subject, your shoulders are a little high and low; 2, the composition should be symmetrical, and you should bring one more shoulder; 3. The subject is far away from the background, and the stains and creases on your background are obvious; 4. See where other documents require to be taken, and whether to take the chest part; Adjust the color slightly, your figure looks too gray. Finally, the second one came out, with a crooked body, and the light was strong and weak. If it's not a portrait photo but a certificate photo, Zhang Cai at the bottom won't work. You just need to modify yours. I don't know why you think it is better than you, but it failed that time.