Thank you! (For the favs too ^^) I don't really know how to explain how I made the box but I basically looked at this reference picture:
[link] and sketched all of the parts on my cardboard (aka Kleenex box lol) before glueing them all together. However, the back is not finished since I had to make it fit in my hand snuggly.
If you need any clarification about the box, you can ask me some questions, maybe I'll be able to give you a more precise answer ^^