Hey This is an Article by Rick Lax that covers that exact subject. This is his way of handling a new idea, I can't say I agree with every step but it's an interesting aproach. The article came from Theory11.
"Every month I get dozens of messages from young magicians across the globe. Often, the letters go like this: “Hey Rick. I’ve got a great idea for a magic trick. Can I tell you about it so you can make me a theory11 artist?” If you’ve written me a letter like that, or if you’re thinking about writing me one, let me give you a couple of tips. Let me tell you what I do after stumbling onto a good idea.
First Step: I make a video of the trick and put it on YouTube.
Often it’s hard to judge a trick’s merit from words alone, so I use my webcam or cellphone camera to shoot a video of the trick, and then I upload it to YouTube, publicly or privately.
If I’m worried about other magicians stealing my idea, or if it’s just not yet ready for the world to see, I go to YouTube Settings and make my video “Unlisted.” That way, only people with the secret link can see your video. That way, you can share it only with specific people you know and trust.
Next step: Modesty. When I come up with an idea, I don’t immediately say, “What a great new trick!”I ask, “Has anybody thought of this trick before?”
If I've got a good idea, there’s a real chance somebody has had the idea before me—somebody who’s already published it. So I ask around before claiming the idea as my own.
If I want other magicians to watch my trick, I ask nicely. I don’t say, “Watch this trick now and comment!” And I don’t post the trick on other people’s Facebook walls. And I don’t tag other people in the video if they weren't involved in the production. If I want to share my new work with people I respect, I do it in a respectful way: via private message or email.
This is an important part of the creative process: It’s important to share your work, one-on-one, with people you know personally and trust.
They’ll likely have ideas that will make your good ideas even better. They’ll offer a different perspective and pull from a different knowledge base. And remember to always thank people for their input. Even if you don’t end up using it.
Now, if you’ve gone through those steps and you still think you have something great, share it with theory11 on the official submission page.
Smart guys like Jonathan Bayme and Dan White watch every one of these videos, and if your idea is good enough, you’ll hear back. If your first idea doesn’t get much of a response (or your second idea or your third), don’t stop creating and don’t stop sharing. I probably thought up a dozen magic tricks before thinking up my first good one.
So work hard, be polite, and remember: Everybody loves a good idea. When you’ve got one, people will take notice."