Final answer:
Proper punctuation for tag lines involves understanding whether the preceding sentence is a statement, question, or exclamation and using commas and end punctuation correctly. In a story, a theme is incorporated through characters, setting, and plot, which should all reflect the central message in a natural way.
Step-by-step explanation:
To punctuate tag lines properly, there are three main rules to follow. Firstly, when the tag line comes after a statement, a comma should precede the tag line, and the tag line ends with a period, for example: She is going to the store, isn't she. Next, if the tag line follows a question, use a comma after the question, and end the tag line with a question mark, for example: You're coming to the party, aren't you? Lastly, when the tag line is after an exclamatory sentence, include a comma after the exclamation and end with a period, like this: That was an amazing performance, wasn't it.
Regarding the incorporation of a theme in your story, start with identifying your underlying message or central idea. Once you understand your theme, weave it throughout your narrative using characters, setting, and plot to reflect and reinforce the theme. The theme should emerge naturally through the interaction of the elements of the story without being directly stated, bringing depth and meaning to your narrative.