I had to router out various depths on specific sides of each piece so that the box would fit together perfectly without gaps. I also decided to sink the base into the box rather than having a visible base at the bottom of the box. Here are some of the individual pieces of the box after they were shaped at the router table and how they all fit together with the base sunk into the bottom of the box.
Once I glued the box together, I built a lid and routered out some space on the back for the hinges. I purchased some small round magnets at a craft store that I used in place of a latch or lock. I used a little wooden heart in place of a locket. I lined the inside of the box with a forest green felt. This was a rewarding project to build something slightly more technical than what I am used to making.