Hi Chris
There's a reasonable amount of time spent planning the head-end, obviously more if there's more going into it. To make sure everything fits in and how to arrange it all. You don't want to run out of space when 80% through as re-arranging everything wouldn't be a pleasant experience. Certainly a label printer is useful but I wouldn't worry about printing labels until everything is wired and tested.
I'd expect most better installers have their preferred way of fitting out so as to leave the panel and other aspects of the head-end presentable and manageable. You learn from experience what works, looks good and leaves access for future modification. A common mistake is not leaving enough room for everything and having little room to fit the kit you need in and having no room for expansion.
http://www.flickr.com/photos/1347818...57624224140934
The LV head-end shown here took up the entire tall cabinet and some of the one beside it, and the kitchen company owner found it hard to believe me when I told him how much space we'd need. Just the other day I looked at this space again to see how to free up some space, as the client is adding a HDMI matrix in and we're already more than full up in the cabinet visible.
Stephen