There’s a plethora of traditional phrases, many of which have a satisfying otherworldly or ritualistic effect. Hundreds are collected at http://www.folktale.net/openers.html (and its companion closings page). Also try “Once Upon a Time, They Lived Happily Ever After”, a thesis summary including a 44 page classification of beginnings and endings of traditional folk stories. About a thousand are listed, most with reference to the culture of the story. It’s by Herrick Jeffers, 353 Dayton Blvd, Melbourne Village, FL 32904, USA , and costs US$11. E-mail HerrickSTR@aol.com.