Finished sewing? Good. Remove it from the table/wood. Starting to feel like a book? Have a play around with it, make sure it opens ok and everything is fastened snugly.
Now what we want is nice clean edges, take it to a printers, local stationery shop or anywhere that has a guillotine and someone you can trust will do it well, some local placed near me do it for free. DO NOT GO TO KINKOS, they are the devil. All you want is enough chopped off to make it squared off and straight.
This book has a curved spine, French style. You don't have to do it like this but I enjoy it. To get the curve you want just start pushing and shaping the spine by hand, when you have the curve desired put a weight on top and position it at the edge of the desk or your piece of wood, we're going to glue it!.