Hmmm ... Maybe not items, but stuff ?
Let's see :
1. Circle Lenses
2. Dyed hair (or maybe not, but dyed hair is very common. Not to mention, match your hair with your eyebrows too :D )
3. Good skin (pale or tan)
4. Fake eyelashes (bottom and upper)
5. Neutral eyeshadows
6. Dark and very black eyeliner
7. Blush
8. Good style (good coordinations with clothes, shoes, accessories, bags and so on)
9. Pretty hair with cute styles (can be different styles though)
10. Definite confident, so you can carry out as a gyaru without being afraid of wearing different and unique style.

Hope that helps ~ Kinda cheated ;P