I think offering praise is important, but it needs to be done right. "What a pretty drawing!" is your opinion. "Wow! You used a lot of red!" in your brightest, most complimentary voice is observable and the child can assign their own value to that. Even the difference between "You are so beautiful," and "You have such blue eyes!" One is a judgement, one is not. Does that make sense?
Not to say you should never say your child is beautiful.
I do it all the time! But I try to remember to put in some objective, observable compliments as well.