Usage patterns
〈人〉は〈事〉が上手だsomeone is good at something
He is good at playing the piano.
お上手を言うto say flattering things
He is always saying flattering things.
〈事〉が上手になるto become skilled at something
I want to become good at Japanese.
上手に〈動詞〉to do something skillfully
He cooks food skillfully.
Expressions
好きこそものの上手なれwhat one likes, one will do well; you become good at what you like doing