Background
I have worked in a professional environment where the process usually goes like the following:
Brain storm idea
Solidify the game mechanics / design
Iterate on design/idea to create a more solid experience
Spec out the details of the design/idea
Build it
Step 3. is generally done with the stakeholders of the game (developers, designers, investors, publishers, etc) to reach an 'agreement' which meets the goals of all involved. Due to this process involving a series of often opposing and unique view points, creative solutions can surface through discussion / iteration. This is backed up by a process for collating the changes / new ideas, as well as structured time for discussion.
As a (now) indie developer, I have to play the role of all the stakeholders (developers, designers, investors, publishers, etc), and often find myself too close to the idea / design to do more than minor changes, which I feel to be local maxima when it comes to the best result (I'm looking for the global maxima, of course).
I have read that ideas / game designs / unique mechanics are merely multipliers of execution, and that keeping them secret is just silly. In sharing the idea with others outside the realm of my own thinking, I hope to replicate the influence other stakeholders have.
I am struggling with the collation of changes / new ideas, and any kind of structured method of receiving feedback.
My question: As an indie game developer, how and where can I share my ideas/designs to receive meaningful / constructive feedback? How can I successfully collate the feedback into a new iteration of the design? Are there any specialized websites, etc?