How to Worry Friends and Inconvenience People

Help yourself to one of the free dogs that people leave outside shops

Spend a whole day in a shop trying to work out who the security guard is

If you take your own bags to the supermarket, why not your own trolley?

Go to the hairdressers and claim to have brought in a picture of a celebrity with the "do" that you're going for. Have this picture be of yourself, taken a couple of weeks earlier, with slightly shorter hair.