Equip yourself with relevant ideas
Read a lot of books, newspapers, and magazines.
Find time to watch TV programs.
Go to the movies once in a while.
Visit museums, parks, botanical gardens, and the likes. Whatever you do, make sure that you learn something new. The more you stock knowledge into your brain, the more interesting you’ll be and the more armed you’ll be, especially in times of surprise attack of interviews.
Just make sure not to bore your listeners with useless, trivial facts.