Here's an easier way to make a book safe! Great for holding cash or gift cards :-).
Find a hard cover book with THICK pages. Novels are usually a safe choice. Don't try this with a dictionary or church hymnal. Dictionaries and hymnals are usually made with wafer thin paper that tears instead of being cut.
Choose an uncomplicated shape. Open your book. Trace the shape onto the book page.
Use a power drill to make holes at each of the corners. Make sure that the holes are equally deep.
Cut from hole to hole with an exacto knife. Like a dot-to-dot ... with sharp blades instead of #2 pencils!
So much faster and easier than the way I used to make book safes!