sparingly reward ordinarily good behaviour.
Of course, that means that unless you also punish bad behavior, it won't stand out from the ordinary good behavior.
but it's difficult to build a positive relationship with someone you're punishing constantly.
It's also difficult to build a positive relationship with someone who is constantly engaging in bad behavior.
Related: Son of Low Hanging Fruit
Another post on finding low hanging fruit from Gregory Cochran's and Henry Harpending's blog West Hunter.