We all have things we can improve on, so do not be afraid to share them. The interviewer will likely take note of these things and may even provide you with additional training or mentoring in these areas if possible to help you excel. The interviewer wants to hear that your weaknesses are not critical for the job you are applying to. Think of a couple of things you could improve upon that are not necessary for the job, and openly share them with the interviewer. You might even include some fun things that are not job-related. For example, you might state, "Cooking is definitely a weakness for me! If you need someone to paint a poster, I'm probably not your guy!" The interviewer will think it's clever, and painting is not essential for a job at Home Depot.
"Cooking is definitely a weakness for me! If you need someone to paint a poster, I'm probably not your guy!"