The wheel has been around for thousands of years. Sure we have improved it, made it more efficient, designed it to stand up to 200+ mph, and slapped fancy rims on it but the basic idea is the same. Unsurprisingly, few good ideas come out of thin air. Often, the best ideas are built on the back of someone else's discovery.
When I took debate class, I was taught that to start writing a case you first had to pinpoint a problem in the status quo.
*NEWS FLASH*
Finding problems with our world today isn't hard. Big surprise. The real difficulty is how to solve them. As a fourteen year old kid I ran headlong into that problem. It was easy to find the leak but not so easy for a high schooler unfamiliar with the topic to plug the hole. I tried writing cases like that for a few years but never seemed to have a solid grip on it.
That all changed when someone told me (I wish I remember who) to start with the proposed solution. What? Start with the fix? It turns out, there are a lot of older, more experienced people who wrestle with many of these same questions. Not to say that high school students can't have good ideas, but reinventing the wheel isn't usually a wise investment of your efforts. Chances are the person who is advocating has already done the research, pinpointed the harms, and has laid out an idea of how to solve it.
This approach has many advantages. First, you already have an endorsement for your case. It sounds so much more convincing to tell the judge, "I urge you to vote for the Affirmative case as advocated for by such-and-such policy expert."
Second, there is likely research available specific to your plan. When you make up your own, you often are forced to use related evidence in a roundabout way to support your case. Opponents can often throw this back at you and say it doesn't apply. If you are using the basics of a proposed policy, then literature already exists explaining your position.
Third, you still have room for personal touch. No need to just cut and paste. You can tweak and adjust the original policy to fit what you need it to be. Just always remember to give credit where credit is due.
There are more benefits, but you are probably getting the gist. In summary, don't work to hard solving the world problems. See what the experts have to say and synthesize their answers. You don't have to reinvent the wheel; just know what size tires you need. And that is how excellence makes an IMPACT.