After finding the grain we are ready to begin. First, we need to pick the dimensions this will often be determined by the paper stock you get. I usually just semi fold it to get an idea of the options I have. For this book I decided to use the breadth of the paper folded a few times and then its height halved.
First, I removed the rough edges of the paper so I could measured it easily.
So then I cut the paper in half, and then half again.
It's easier to use your knife rather than a pencil to mark half way points!