If you have a prototype for an idea, then you can take inventory of peoples' interest in it using the
Recruitment Thread and hammer it out using the input you gather from there. Once you've established enough to create an OOC thread, it will blossom further from there.
So basically, it's important first of all to have a functional premise/framework for a thread. Enough to actually give people a solid image of your idea. From there, you can present it to others and they'll be able to help you.