It came to me recently that there are two ways to tell the girl of her beauty in English: "You look beautiful" and "You are beautiful". The latter feels much more personal for some reason, even though both touch upon the same idea in a very similar manner: as if I reach to the soul of the person I'm saying it to, and not just the outer shell. Maybe I'm wrong; I'm just figuring it out.
Certainly, the best way to go would be honestly: compliment what you find attractive or worthy of praise. Even then, there are different kinds of honesty: I'm sure most females of any age will never find something like "Your body is good enough for you to star in porn" attractive.
So, let's suppose I find the girl I'm interested in physically attractive - how do I compliment that without any subtle negative or undesired connotations ("I like your body", which is much more sexual than aesthetical)? Either of the above, or something else?
The same question applies to any other kind of compliment: what do I say and how do I say it?