What do I say about why I left my last job? - what worked for you?

I have an interview next week and I am unsure how to explain why I left my last job as an accountant. I have been trying to stay organised about it. I also do not want to seem like a risk. Do they ask follow-ups?

Practise it out loud with a friend. Mine felt natural after the third try.

Keep everything in writing and save the confirmation numbers. It saved me later.