Objectives: I decided that I would make this the sort of piece two men sitting at a bar or crowded restaurant might be discussing. To that end, I made the beginning sound like the man was turning in to face his friend via fade in. In addition, I elected to use some brief sound effects to accentuate certain aspects of the story (the dice toss, the cheering). I also went through and removed noise as best as possible, though preparatory breaths were harder than most.
Loops: I used crowded restaurant music, looped in order to extend and deliver the ambience associated with the piece as I decided it didn't make sense to use dramatic music or music designed to evoke the humor associated with the piece. I had to carefully monitor the volume in order to ensure that it was present but not overwhelming. I also made sure to extend it at the start and end to make it seem like the piece took place during the scene, rather than the scene occurring as part of the story (and vice versa for the sound effects).
Beginning: I elected to use a lead-in in the form of the continued chatter, as earlier described. This, combined with a fade in from the voice, sets a scene prior to the events of the story, which, hopefully, places the story and provides framework.