My opinion on NDA’s is that you need them! Don’t let anyone tell you differently. Sometimes,
if the product is not unique like t-shirts, jeans, etc. then it’s just a matter of doing your designs and getting them out there to the market place. But if the product is unique, then protect it. It is your Intellectual Property.
Research your idea on US Patent Office website - you can do this yourself for free. If you proceed, your attorney will check again for you before you start writing a patent. If you were wrong and there is a patent that you would be infringing on, think of something else or it is possible to improve on another persons patent or license it from them to make your own. I am not an attorney obviously so talk with a pro before you take my word.
In the event you have a truly unique idea, then start the patent process. Draw your idea best you can and write it down on paper and date each piece of paper. Now this is proof that the idea is yours. Sounds crazy but it’s not. Patents are expensive but don’t skimp. You need a well written one. There are good and bad attorneys that do patents. The better written it is the better it will hold up in court if you need to use it.)
I could be wrong but this is how I feel you have a better shot at success! Good luck and don’t be afraid to fail. Failure is only failure if you don’t learn from and move on!