I'll be sure to check out your sites, Alliwine and Leadfoot.
Nasum_human, as far as soloing goes, my approach when recording is to pretty much try anything. For the most part, unless there's something I really want to get down, it's almost always improvisational at this stage of the process. Of course, unless I get a good take, I wouldn't hesitate to re-record. There's always a certain amount of tricks I have up my sleeve...it gives me the opportunity to stake out a direction of where the song is going in my head.
As far as song writing is concerned, my same approach to soloing also guides my writing process. In other words, I have no clue what I'm doing before I get there. For many of these tunes, the melodies are written on the spot. In some instances, I don't even have any riffs ready, so I just experiment on the spot until something catches my ear. This may not be the best way to approach song-writing, but I feel it gives me a certain degree of innovation and freedom.
Once I've gotten everything down, and I'm happy with it, then I will actually re-learn the way I performed the solos on the recording for live situations. Often I still end up improvising on stage though.
Matt :)