The best answer for "how's life?" is subjective and depends on the context of the conversation and your current situation. It's essential to be honest while considering the person you're talking to and the level of intimacy you share with them. Here are a few possible responses:
Positive response: "Life is great! I've been doing well and enjoying some exciting experiences lately."
Neutral response: "Life's been good, thank you. How about you?"
Casual response: "Not too bad, just taking things one day at a time."
Personal response: "Life has had its ups and downs, but overall, I'm content. How about you? How's life treating you?"
Remember, it's okay to share your feelings and emotions, but you don't have to divulge personal information if you don't feel comfortable doing so. Gauge the situation and tailor your response accordingly. The key is to be genuine and maintain a positive and open dialogue with the person asking the question.