One definition of a hook is a musical or lyrical phrase that stands out and is easily remembered. Definitions typically include some of the following: that a hook is repetitive, attention-grabbing, memorable, easy to dance to, and has commercial potential and lyrics. A hook has been defined as a part of a song, sometimes the title or key lyric line, that keeps recurring.
Creative accounting is a euphemism referring to accounting practices that may follow the letter of the rules of standard accounting practices, but deviate from the spirit of those rules.
Creative Problem Solving (CPS) is a structured process for solving problems or finding opportunities, used when you want to go beyond conventional thinking and arrive at creative (novel and useful) solutions. You can, of course, choose to solve problems in conventional ways. Indeed, most problems are solved using known solutions.