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 a social media manager. I am in Dallas, in case local advice matters. I also do not want to seem like a risk. Do they ask follow-ups?

If a company has been in the news for layoffs, you can mention that. Often the interviewer already knows.