When I'm writing research work, I have a tendency to collect all my
sources, write down every quotation I think might be pertinent and then
take a week or so to let all the stuff I've read sort of rattle around in
my brain. Sometimes this process doesn't even seem conscious. I'll wake
up from a good night's sleep and an IDEA! will have presented itself with
how to collect this stuff in a cohesive whole.
I'd have to say I've never found much success with prewriting techniques
that involve actual, physical writing. I have a tendency to keep it all
head until it's ready to come out in somewhat of an organized fashion.