Billy Crystal's Persuasive Technique
"You look Marvelous!"
Flattery will get you everywhere. Billy Crystal's character, Fernando Lamas, made it popular again to complement others. Comedy is funny because it so closely resembles real life . . . just not quite.
When people feel liked, they tend to reciprocate the feeling. When you actively search, find, and verbalize other's virtues . . . it makes people feel good about themselves . . . and consequently feel good about you.
More importantly, based on the principle of congruency people tend to behave in a manner consistent with the virtue you declared (assuming that it truly existed beforehand).
The opposite is to focus on other's shortcomings. The easiest thing in the world to do is to find fault in others, it is not a noble virtue.
The counterfeit of finding other's virtues is flattery in return for agreement. This is usually more frowned upon than broadcasting another's shortcomings.
With all that being said - I must say, "Darling . . . you look Marvelous!!!"
Finding Other's Virtues is but one of the 12 Triggers of Persuasion.