I was unable to find any decent quality images of DSiWare templates, so I decided to make one. I tried my best to mimic the dual border design used on several eshop games.
I also decided to make a version for sets of 6 DSiWare games, which I'm dubbing Game Packs lol. The images are partially hand drawn, and I tried to mimic the DSi home screen. I recently figured out a way to add my DSiWare library to launchbox, and grouping them saves a considerable amount of storage space.
If you want to know more about that, check my forum post for a tutorial.