Preparing for my first interview in 9 months - 5 weeks in

I get tongue-tied when I am asked about my weaknesses. I have been trying to stay organised about it. I have practised answers but they sound stiff. What calms you down?

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

Arrive early, drink water and take a slow breath before you walk in. It sounds simple but it helps.