Among the topics that were explored in the course Intelligently Interacting with Others (IIO) were Social Psychology and Influence. Complimenting people was discussed as an influence approach.
"But isn't that lying? Wouldn't that be dishonest?" wondered a participant. "Are you trying to say you can't find even one good thing in a person for you to be able to genuinely compliment?" the Prof remarked. You can even go with "Hey, nice shirt" he added. "It works still".
Compliment people. Be able to find good things in people and genuinely compliment them.