I tend to compartmentalize so I may come up with a concept on an acoustic guitar. The concept may be as simple as a small melody line or a full song with chord changes etc and so on. When I start tracking it seldom stays the same in the sense of my original concept of it. The melody line might stay the same but the production, once it gets going, tends to veer off in wildly unanticipated directions.
I like this. And I like the ability to track those conceptual changes relatively easily in a modern DAW.
Regards,