Just found an awesome how-to video by NESComplex on creating universal cases for your NES Collection. He goes over design, to print to how to construct the cases for your NES library.

"In this update video I demonstrate the storage system I use for many of my NES games: Universal Game Cases UGC and printed box art covers from www.thecoverproject.net. I show how to print them from PowerPoint, and modify the game cases for NES games using a multi tool. I also address using DS Cases for GBA games and the problem with doing this if you live outside the states. If you know of any websites abroad, let me know and I'll add them to the description! I hope it helps!"