Lifetime Video's Example of a FlashBack

Flashbacks are a very clever element to use in your film and have different effects on the audience; they are very helpful in situations such as setting a transition through the past and future. There are many different ways of creating this effect, the most common ways of doing this are, Blurring it, showing it deliberately Monochrome, add a misty border around the edge of the screen, apply an echo or other sound effect to everyone's voice, in animation or comics, apply an Art Shift, for books, changing the typeface, in comic books, changing the panel border style.
We chose to use this element in our film as we wanted to create the effect of a time passage, from the past to present where the little girl is shown and the ways she was taken etc. then what the little girl later grows up to become.