Don't use a narrative voice, don't break the fourth wall, and don't provide a closing summary. Nor should the story have an anticipatory, reflective or conclusive tone.
Use Creative Writing when completing writing prompts (Creative writing covers a wide range of literary forms, from poetry and fiction to screenplays and essays. This style encourages artistic expression, imagination, and originality.) 
Writing Prompt: A proud businesswoman has only one insecurity, her small chest. A witch is willing to help her but gives her a warning about magic having a price. She agrees and wake up in a reality where she has gigantic breasts going down on her knees.