Difficult to answer as I'm in a state of flux at the moment (because of the advent of WikidPad), moving from mainly Word Processing to mainly Wiki -> WP.
But as an example, the one I've just about finished is the basis of a Testing Plan for some software integration we're doing at work.
Because the whole thing is pretty convoluted (and I wanted to play
) I used WikidPad.
The process started by just collecting the foundational information, requirements and other data, then linking all the base information together. Then I started writing the plan, linking to data, requirements, etc as it fit; in a similar manner to the little wink I posted in the WikidPad Review
I added issue
tags to mark what needed testing and what the results should be. Used attributes to mark certain pages. Reusing Insertions was of great benefit (Insertions in WikidPad are like Included Text, some page that can be re-used in another page)
When I had done all I could in WikiPad I exported it to HTML and posted it for comment from my peers.
Once it gets the green light it will need to migrate to an environment where the actual testing data can be collected and collated.
But overall I was pretty impressed with how the Wiki performed in enabling me to marshal my thoughts. The process going from bare bones (which is what I think you really meant by "outline") to detailed was very smooth. But as was mentioned elsewhere, Wikis really come into their own when there is a lot of previous material that can serendipitously finds its way into your pages because of the Wiki Linking system.