I did a test with cardboard, planning to migrate to balsa wood, but after the project was completed, I liked the result so much that I kept it as it was.
Tinted transparent paper
Table Saw or Router
Corel Draw (R) or any other vector-capable software
Danish oil (or any other wood stain/finish)
Step 1: Preparing the project
For your convenience, and out of my generosity, i made the Corel draw file available HERE.
Just open and you should be good to go. Just a comment: there are other decorations in the file, they are hidden and print disabled (see the layer named "non select").
Follow the guidelines for the power and speed depending on the cardboard thickness.
Since the design is very complex, I suggest to either increase 10% the power or decrease 10% the speed, because you don't want to end up with parts not completely cut through, and need either to redo the job or -even worse- to cut the pieces manually with a knife!
Step 2: Cutting
You will notice that one side has the typical "laser burns": don't worry, we'll take care of this the next steps.
Step 3: Finishing the exterior side
Lay the pieces on a mat or cardboard, with the side with "Laser burns" down.
With a steady flow, spray several coats of poly, letting it dry within coats.
The poly will dry fast, because the cardboard will absorb it. Be careful not to insist too long on a spot, or you will wet the cardboard and make it look darker.