Don't worry if you get a question that you haven't prepared for. You can usually use ideas that you prepared for a different topic. For example:
Describe a piece of advice that you gave (or that someone gave you)
Why not say that you advised your friend to visit London? Then you could use all the good vocabulary from this lesson. Or you could use this lesson to talk about advice that your father gave you. For example, say that your father told you to work hard. Then you could use great vocabulary such as 'major influence', 'hard-working', 'role model', 'set a good example', 'positive outlook on life'.
Think quickly during the one-minute preparation time: What can I use that I've already prepared?