I freeze in interviews, tips? - first time posting

I get tongue-tied when I am asked about my weaknesses. Any experience at all would help. I want to come across as confident and honest. How do you prepare answers?

Prepare three stories with a clear beginning, action and result, and adapt them to the questions.

Thanks for writing this out. I went through something close to it last year, and it settled down once I kept a simple log of every call and form.