I freeze in interviews, tips? - what worked for you?

I have an interview on Tuesday and my stomach is in knots. I would rather hear the honest version than the polite one. The role is similar to my old job as a store manager.

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.