I've figured it out... partially. Find people's weaknesses and use it against them but to improve yourself.
You know that friend who's constantly criticizes your lifestyle or thinks they know best? An advice from their mouth sounds more like an imposition? Their humble know-it-all gestures reek of zeal? Or what about the parent who's on your case? I know as parents, that is their duty but sometimes you don't want to hear it, those consistent sly jokes they make because they know which string to pull.
Gain the confidence through other's shortcomings.