I freeze in interviews, tips? - 4 months and counting

I get tongue-tied when I am asked about my weaknesses. I would rather hear the honest version than the polite one. I have practised answers but they sound stiff. What calms you down?

Keep everything in writing and save the confirmation numbers. It made the follow-up calls so much easier.

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