Yeah, indeed. The word to eject from the process is "formal", not "documentation". Write stuff down however it works for you: be it email, IRC logs, napkins, whiteboards, whatever. Refine as needed. Write summaries every few ideas.
If the problem is of the right size, bang out prototype scripts and let these serve as "documentation" too.
But scrap the endless cycles of proposals, reviews, designs and revisions. Do that stuff implicitly.
Yes I think this hammers an important point. Write with what helps you think, For me It has to be an uber size blank sheet of paper and I just start planning. After the paper I can usually go to a laptop an either make a rough prototype or at least a structure in code. I don't know why I can't seem to code directly.
To repeat do what helps you think faster/clearer/better
If the problem is of the right size, bang out prototype scripts and let these serve as "documentation" too.
But scrap the endless cycles of proposals, reviews, designs and revisions. Do that stuff implicitly.