Step 1: Cutting out a 2D shape.
This shape was acheived on the third attempt through trial and error.
Step 2: Folding
The inner flaps fold in on itself.
Step 3: Locking the sides.
The sides have a locking system which is cut from the inner panels.
A cleaner, more crisp edge might have been acheived by having 2 locks instead of 1.
Step 4: Completed model.
You can see that there are gaps between the edges.
One way of improving this would be to fold it sharply (but the difficulty of this increases with the thickness of the paper).
