"How are you doing?" is the English phrase commonly used to ask about someone's well-being. It is a simple and polite question that can be answered in various ways depending on the situation and relationship between the speakers.
If you want to sound more casual, you can respond with "I'm good, thanks for asking!" or "Doing pretty well, thanks for asking. How about yourself?" If you want to sound more formal or interested in the other person's answer, you can say "I'm doing well, thank you. And how about you?" or "I'm doing okay, thanks for asking. How has life been treating you?"
Overall, the most important thing is to be genuine and respectful in your response.
