Nintendo DS Lite
1. The model comes in two pieces, each representing one of the dual screens. Assemble each of these as though you are assembling tiny rectangular boxes. Be sure to cut a slit in the bottom screen meant for the cartridge. If you notice, there is a white rectangular blank piece on the template - fashion this into a pouch to be placed on the inside of the bottom screen piece - it will hold the cartridge and prevent it from falling all the way into your bottom screen piece.
2. You will notice two even smaller boxes. These are meant to be glued onto the bottom screen to hold the hinge for the screen above. Assemble these, poke two holes and slide a short toothpick/wire between the two holes as a hinge.
3. Cut out the last piece (where the microphone of the DS sits), wrap this around the hinge you created in step 2. Attach the top screen piece to this.