These are never "sit-down-and-do-it-all-in-one-go" builds. They usually take months. Even when I have, say, an eight-hour stretch available, I'm constrained by drying time, for glue, putty, and paint.
My designs aren't the step-by-step process of a kit build. There's no carefully thought-out-and-tested build sequence. So things happen - glue something down solidly, only to discover I really should have put this other thing in there first - that kind of "thing". So then I do something to cover the mistake - and that can change the look away from what was planned.
Another thing that happens is that as I'm digging through my parts bins looking for that perfect part, I find other parts that persuade me that they 'belong' in the build. Or I might use something - a CD jewel case, for example - that works well, but doesn't lend itself to being trimmed or resized; and that changes the design yet again.
Also, day-to-day my ideas will change, based on who-knows-what - an idea or event at work; "new" parts coming to light; someone saying "what if you did this?" Sometimes it's because I have forgotten that I meant to do thus-and-so, or I find I out I simply can't do thus-and-so (can't find a part, or can't figure out how to physically do it.
So, for all these reasons (and probably more I can't think of right now), my "design" changes - the model seems to build itself, in a way.
Does this happen to anyone else? I look at your gorgeous builds in the Readers Gallery, and think "I wish mine would turn out to plan, like these guys' did." I'm guessing, though, that by this time, for better or worse, my build methodology has standardized into a "Marmite-fueled, Chinese music (Thanks, SiaoMouse!

