There are three time-tested approaches for putting your ideas across to arouse interest and enthusiasm.
The first is to use a fishing pole.
Since it is very difficult to ram a hook into a fish’s mouth, the fisherman casts his pole temptingly near the fish. The fish is then enticed to come to the baited hook. The point: Don’t appear too anxious to have your idea accepted; just bring it out where it can be seen. People will accept your idea—especially when they consider it their own. Say something like, "Have you considered this?" instead of, "This is the way."
Similarly, "You think this idea would work?" is better than, "Here’s what we should do!" Let the others sell themselves on your idea; then they will stay sold.
The second is to let the other person argue your case for you.
Present your own objections—before others have a chance to do so. Ben Franklin said that the way to convince another is to begin by stating your case moderately and accurately. Then he suggested saying that you may be mistaken about it—which prompts your listener to convince you of the correctness of your position. People feel compelled to react when an objection is raised. In contrast, if you initially present your idea in a tone of great confidence and arrogance, you may get an opponent.
Abraham Lincoln used a variation of this technique in selling his position to a jury. He argued both sides of the case. But there was always his subtle suggestion that his side was the logical one. An opposing lawyer once said that Lincoln made a better statement of his case to the jury than he could have made himself.
Technique three: Ask; don’t tell.
Perhaps the most famous such sell was made by Patrick Henry. In his famous "Liberty or Death" speech, notice how he used this approach: "Our brethren are already in the field. Why stand we here idle? Shall we lie supinely on our backs? What is it that gentlemen wish? What would they have? Is life so dear or peace so sweet as to be purchased at the price of slavery?"
If the same were said in statements, the result would have been antagonism instead of a spur to action.
Again, three techniques for selling your ideas: (1) Use a fishing pole, (2) Let someone else argue your case for you, and (3) Ask, rather than tell. The latter is described in detail in parenting Without Stress.