A catch phrase is a short cluster of words that provide an intellectual and emotional anchor for our listeners. The phrase is chosen so that by saying a little repeatedly, we are saying a lot.
For example, in a recent persuasive speech about comprehensive sex education, Karlene repeatedly used the phrase "the teen's choice to have sex." She used the phrase at least seven times. She was painting the teen as an intelligent decision maker. The phrase fit nicely into her thesis that we should help teens understand the consequences of their choice.
In another speech, this one opposing abortion, Cameron repeatedly referred to abortion as a solution for the "inconvenience of unwanted pregnancy." Again, I counted sever or eight repetitions of the phrase. By repeating this catch phrase so often, Cameron trivialized the motive of those who seek abortions, thereby weakening their position.
Developing catch phrases is much like the skill of clearly stating your thesis. It gets to the "heart" of your message and makes it unmistakably clear to your listeners.
Try to find a phrase—a few words—that capture the guts of your message. Try the phrase out on your friends to see if it communicates to them what you intend. Build it in to your speech, repeating it 5-6 times so that no listener can possibly miss it. By doing so, you ensure that even if the listeners don't remember much of the content of your speech, they will remember the catch phrase. They may not even remember who said it, but it can alter their thinking about the topic.
Let's go fishing.