Sometimes it might be appropriate to give your subject some space. When photographing people, you can make a more interesting image by creating space in front of them. This conveys the sense that the person in moving into the scene.

No space in front of subject Moving car, Norm Heke, 2009. | 
Space created in front of subject Moving car, Norm Heke, 2009. |
See how Brake has used space in these two images: