Via the Facebook Fan Page, Matthildur asks:
What's your opinion of Flashback sequences? Do you find them annoying? Do you think that all the flashbacks should be related? or do you think it's a lazy way of explaining backstory? I'd really like to know?
It all depends on how they're used. In the wrong context, yes they can be lazy ways of explaining backstory but there are plenty of films that have used flashbacks wonderfully. Think of all the flashbacks in Citizen Kane and how they add to the fabric of the story.
When I read your question I immediately thought of both Batman Begins and Watchmen, both of which used flashbacks to illuminate the backstory of their main characters in a way that didn't fell lazy or weak. What makes the difference there is that the flashbacks all fit into the fabric of the larger main story. It was necessary for us to see Bruce Wayne's parents being killed and how he reacted years later to their killer being freed because all of that played into his character arc in the "present." In fact, it was the root of his character arc to such a degree that not showing us all that information would have resulted in an incomplete story.
Where I've seen flashbacks go wrong is when they're used to show us things that have nothing to do with the plot, and really don't even contribute to the main character's arc. Backstory isn't always essential to the main narrative. A lot of writers make the mistake of thinking that if they give their characters an angst-ridden history, or some unrelated tragedy in their past, that the audience will automatically relate to them.
I've seen this happen more than once. Deep in Act Two, there'll come a time when the main character has a long, dialogue-driven scene with the second lead. There'll usually be some revealing confession like their father beat them when they were young, they got pregnant and had an abortion at sixteen, or grew up not realizing just how stupid The Nanny really was. They'll get this off their chest, and the confession will make the second bananna realize "Wow, there' s more to you than I thought all along. You're senstive and deep."
Most of the time you can tell this scene is a quick patch on a note that likely read along the lines of "Your main character has no depth. Can you flesh them out a bit? Maybe tell us something about their backstory?" And since this scene is often forced in after the fact it rarely has any real connection to the plot, the themes or the rest of the script. It's filler.
Usually when I see a scene like this in a script I'm reading for the writer, I'll tell them that it doesn't work for me. I'll mention that it's all telling and no showing, breaking one of the screenwriting "rule." Often I'll suggest that we should "see" what's revealed via this scene elsewhere in the screenplay.
And what do they usually do in the next draft? They turn the monologue scene into a flashback. Now it's not "telling," it's "showing," right?
No, it's still "telling" us in a way - because it's such an on-the-nose way of revealing backstory. If I'm aware that this whole scene exists only to give exposition, then it's on-the-nose. It lacks the depth of something like the Batman Begins flashbacks, which feel utterly necessary to understanding the story and the Bruce Wayne character.
So you're on to something when you ask if it helps for all the flashbacks to be related. I say it's even better when the flashbacks reveal things that are essential parts of the story.
UPDATE: I swear we didn't plan it this way, but Scott covers some other flashback questions today over at Go Into The Story. I don't plug him enough, but his is one of the more informative writing blogs out there. Bookmark it if you haven't already.