James Bond (Sean Connery): So your chauffeur informed me. He is a rather intelligent young man by the way.
Connery in Istanbul, in From Russia With Love
Have you ever been caught out by a disparaging remark? Course you have. Ever been let down by giving an honest compliment? Never. And you will be glad you did. Not talking about crawling here, I mean a straight-up compliment. Go tell her/him/kid-down-the-street you have noticed how hard they have been working or what a good job they are doing (if they are).
Further reading: Compliments Cost Nothing