Press the book under a weight like books/bricks for as long as you can, a few days is good. Add touches where you please, I did a bookmark.
I hope you learnt something from my tutorial, preferably how to make a book. The reason I make books is because I love it, the satisfaction is immeasurable after so much hard work has gone into it. Check out the extras to see how I do other stuff like embossing (which is in this book I just thought it'd make a nice mini-tutorial).