You can stretch the facts, combine different events or even modify a joke to fit. If you are using an existing story, the workbook Storytelling from Toastmasters International offers the following points to consider. Different age groups prefer different types of stories. Generally, younger children enjoy stories with plot and action. Older children and adults like stories with more humor and interplay with characters.
All ages enjoy rhythm and movement of event in stories.
Stories should be well paced, with few slow and no dull spots. You also need to consider how your story will fit with other events. For example, if the story will be used at the beginning of a campfire, it should have a lot of excitement and energy. If the story will be used near the end, it should be quieter and more thoughtful. Stories are usually better told than acted out.