Actually I don't think the stylists are really to be blamed. I've seen Liu Jing in a range of outfits/hairstyles/make-up, both modern and traditional and although she looks more flattering in some styles as opposed to others (just like everyone else), generally, I don't find her very attractive-looking. Doesn't help that she looks very matured as well. ZZR's outfits are actually among the prettiest of the female characters and Liu Jing has also been given a variety of different hairstyles but somehow, she just doesn't look stunning and I've always pictured ZZR to be very beautiful, appearance wise. Like what someone mentioned, even Charmaine looks better and let’s not even get started on GYY, Kathy Chow, Sheren Tang or Angie Chiu.
Lu Chen (who plays Yang Buhui) is similarly, a newcomer under CM and a teeny bit more experienced than Liu Jing but she's not being promoted as heavily even though I personally find her much prettier and a very decent actress as well.