Nope - would you like me to make an example texture, so you can see how it's supposed to work?
Basically, it's the same idea behind the ninja turtles texture:
Description: Glowstone = Dojo Wall Panels
Sandstone = Dojo Floor
Diamond Sword = Katana
Gold Sword = Bo
Iron Sword = Nunchaku
Stone Sword = Sai
Villagers = Ninja Turtles
Snowball = Shuriken
Golden Apple = Pizza
Stone Slab = Pizza Box
(click to see more info)
For example, they edited the texture of a golden apple (an existing item) to make it look like a pizza.
(Just don't press the new item button in the texture editor and you'll be fine). Maybe keep a handwritten list so you can keep track.