Personally I find that mild flattery does often move things along more pleasantly than outright candidness.
While excessive insincere praises intended to put the other person into the position of owing something to the flatterer is cheap and cheesy (and often reveals emotionally "needy" personality out for approval), a little flattery does help to quickly warm up first meetings or bridge relationship gaps.
For example starting off your conversation with a statement like "You look gorgeous" is surely better than starting with "You forgot to put on your make-up today".
By offering positive reinforcement, you are not only making the person feel good about herself but you are taking the small extra effort to actually show the person that you care about how she feels. She may come back with "I don't have my make-up on" to which you can respond with "You still look good". But when you say "I couldn't even tell you did not have make-up on" or "You look like you have make-up on", you've crossed over to the excessive insincere praise.
Flatter someone today!