I just don't think such a thing needs to be described. If I want the character to be attractive to me I'll think of them as attractive. That's going to be people's base line anyways since it's their fantasy. I don't need a writer describing the characters perfect face or hourglass figure. It's a waste of words and may just diverge from what I wanted to picture the character as.

Generally speaking I think that character description should be left at a few characteristics that are more striking than the characters overall look.

That aside though I do think it would be great to have more characters have traits that are considered unattractive or at least out of the norm. Think large noses, not skinny, short men / tall strong women, etc.

It all really comes down to what purpose you think story telling serves but I think the "it's not real life" excuse kind of doesn't take into account that if you're saying one thing is the "fantasy" that you are agreeing with society at large that the other trait isn't or shouldn't be. In reality we collectively decide what "attractiveness" is. Any survey of famously attractive people though the ages will show that this standard shifts dramatically over time.