Setting up your proposal
Describe your project in a few words. Make it pitch perfect so people love your idea right away.
Here you have the space to describe your project more detailed. Still: Don't make it too long. Take your time to make your description short and concise. Nobody likes it to decrypt half-baked content, right?
After you published your proposal, all people in the network who match the expertise / profession you are looking for will be notified. The better your pitch is, the more people are likely to apply. Of course you knew that. Still, why not saying the obvious from time to time...