This exercise involves several steps. The only material you need is a pen (or pencil), a piece of paper, and a timer.
Once you have all your materials set up, picture a character in your head. After you have thought about the character for a minute or two, set a timer for five minutes. Write during these five minutes. After the timer buzzes, read over what you have written.
Next set another timer for five minutes. Now try to convey the character from the perspective of another person. Once the timer buzzes review what you have written again.
Before you set the timer a third time imagine how your character would behave in a foreign country. Write about how the character behaves in this situation.
The fourth timer is set for only one minute. Now try to convey this character in just one sentence.
By the end of this exercise you should have a much better sense of this new character that you have created. You should know how they would behave in all sorts of strange situations. If you like this character you can even keep him or her around for a longer project.