What Can I Do to Keep my Story Interesting?

Today, we have a question from a fellow writer, as always.
What can you do to move your story along when it gets to a slow point?

We all face the problem where your story or book starts to feel like it's dragging on, even when we're nowhere near the end. Some writers ignore it, and their books suffer. Whenever I feel that the story is getting boring, or the characters seem bland, I throw in a twist. Think of your book as if you're the reader. What would be a shock that spiced things up, but kept it realistic for your storyline?
Things like adding a new character into the mix or even killing one add a punch to your book. I know most books can't just have people dying left and right though. So, maybe a dramatic accident where someone is injured. Maybe your main character flips in science class? It's up to the writer how to add the punch in. Whichever way you choose, it should be a wake-up call to readers that your book does have twists and turns. Don't let things get too out of hand though. If you want to see an example of plot twists, take a look at my book, Flashbacks of Juliet. There are a lot in there.
I hope that helped with your dilemma. Just remember, think of yourself as the reader. What would make you go, "Oh my God, I can not put this book down!"?