Flashbacks! F! Yey!!
I don't do flashbacks actually. I always heard they were bad juju and too many of them ruin the story. So I never really done them. I have in the past and it always started with FLASHBACK written in large letters at the beginning and END FLASHBACK at the end. That was my segue.
Smooth, right? Just like sandpaper.
Now, I do bring up things that have happened before, but I give more of a synopsis rather than explaining everything that happened and show it like a normal scene in the book. I guess I'd change my mind if the story absolutely called for it.
What about you guys? What do you think of flashbacks? Do you use them? How do you segue into them?