At the end of the chapter "Narrative Skills" Keith Johnstone in his book Impro offers a few simple guidelines for successful improvisational stories:

• interrupt a routine — describe a situation, then break into it with something unexpected (but not "clever"); when that becomes standard, interrupt it in turn
• keep the action on stage — "... don't get diverted on to an action that has happened elsewhere, or at some other time ..."
• never cancel the story — as a narrative progresses don't do a reset to the initial situation, but do if possible bring in elements foreshadowed earlier

_{(cf. AbsurdJuxtaposition (1999-10-21), Yes, and... (2012-11-14), Positive and Obvious (2012-12-12), ...) - ^z - 2013-01-20}