Last Monday on Hawaii Five-O, we started out with one of the team members washing blood off her hands and then asking a nurse for an update on the main character Steve McGarrett. She looks over to a gurney and I think the entire audience's heart stopped because well, the man is Steve McGarrett. If something happened to him, it must be pretty bad because he's a Navy freaking Seal who has a bit of Superman in him. So, you get the picture. The story is going to be good because it's starting out bad.
But then we do a time jump to eighteen hours earlier. Which would be okay, but the show didn't leave it there. We jumped back to the hospital, then back to the story, then forward to the hospital. I was seriously getting whiplash and was confused a lot of the time about the sequence of events. I couldn't understand why the writers were being so lazy. But, you see, book writers do that, too.
A lot of times writers are tempted to put a flashback at the first of their story because something really awesome happened and they use that technique to draw the readers in. Just like on Hawaii Five-O. But, the thing is, flashbacks and dreams are really hard to do well. It's too easily spotted as writerly laziness and readers feel like you've pulled a bait and switch on them when they realize that wasn't the true beginning to the story. Hawaii Five-O not only did this once, but many times, because they were using the technique to highlight all the exciting parts of the story and it ended up being more confusing than anything else.
A better technique is to use the "exciting event" you are trying to highlight in your flashback and make that the starting event of your story. Or, if it's too far in the past, drop little hints and pieces of it into the story, unrolling it as part of your character's makeup as well as to keep the reader guessing as to why your character is behaving this way and how he's grown or regressed since the event happened.
The key is to keep your readers with your characters---feeling what they feel as the story unfolds and letting them experience the events vicariously through your character's eyes. If you're constantly going back in time or using dreams to further your plot, then you're taking the easy way out and agents and editors will know. Use your imagination and your skills to keep your story present and real. Drop the hints, play the story out, and keep your characters relatable.
You won't be sorry. And you won't have people shaking their heads and saying, "What? I'm so confused . . ." (Hawaii Five-O writers I'm looking at you.)