Gyaru x Serious glasses girl.
The right combination.
It's either that or Gyaru x Tomboy.
Or Gyaru x Office Lady, or Gyaru x Otaku.
Maybe I just really like gyarus.
Well contrasts are where it's at, and Gyaru happen to contrast very well with Nerdy types, Office Lady or Tomboy (who likewise contrast well with a lot of girls).
Though I generally like "flashy" type x Bookworms/ nerdy type.