D is for details. As I tell the students I work with, there's all the difference in the world between "a bottle of soda" and "a two-liter bottle of Diet Sprite." Because it's specific, the latter has credibility. We believe the latter much more than the former, and if we believe the details, we're more likely to believe and have sympathy for the story the student tells. But be careful not to overload the PS with too many extraneous details. A few well-chosen details (smells, shapes, tastes, sounds) will help your PS come alive.