The idiom "harp on" means to focus too much on or emphasize something, often to the point of repetition. It can also imply that someone is unwilling to let go of a particular topic or idea, even if it has been discussed at length.

The idiom "off on the wrong foot" means to start something with a mistake, misstep, or misunderstanding that leads to failure or negative consequences. It can also mean that someone is not behaving appropriately or has made a poor decision from the beginning.

The idiom "on the ball" means being alert, aware, or attentive. It suggests that someone is always ready for anything, and they're in control of their actions and decisions. This phrase can also mean being organized, efficient, and professional in one's work or business dealings.

The idiom "willy-nilly" means doing something without any planning or consideration, often impulsively or recklessly. It can also mean making decisions or taking actions without a clear understanding of the consequences.

The idiom "make light of" means to treat something lightly or unimportant, often by minimizing its seriousness or importance. It can also mean to belittle or ridicule someone or something. The figurative meaning is to mock or dismiss someone or something in a derogatory way.