Orchestration is a form of personel management: who plays what, when they play it, and sometime even where they play it. Composers don't always think of orchestration this way, and it might be useful to look at other art forms in which this aspect is more explicit: the best playwrights and choreographers, for example, manage the exits and entrances of their players supremely well.
One of my pieces-in-progress is a wind quintet, a tricky genre due in large part to the fact that continuity has to be provided by players who have to breath every once in a while, thus inviting lots of entering and exiting in a continuous stream of changing scoring patterns. But how might those patterns be sensibly organized, in a piece, for example, in which every combination of instruments is used only once?
I recently stumbled onto a nice solution to this suggested by a stage work by Samuel Beckett, Quad, a "frantic mime" for four players, lights, and percussion. Beckett wanted to organize Quad on the basis of a sequence in which every combination of the four players would be used, each combination in the sequence differing from its neighbor by the entrance or exit of one player, and when a player exits it is always the player who has been on stage longest.
It turns out that the conditions Beckett set were mathematically impossible to realize with four players (making Quad another example of an inexorable and imperfect logic at work in Beckett), but solutions to what is now known as the Beckett-Gray code have been found for other numbers, among them n = 5, which immediately struck me as an interesting premise for a wind quintet, in which the player who has played longest is most deserving of a breather. I have long used Gray and similar codes in other pieces (I recently mentioned a piece with some "anti-gray" coding), but I'm especially taken with the way in which the Beckett-Gray can respond to particular musical problems (in this case, continuity and the need for individual musicians to pause). I expect to use it elsewhere, and not only in orchestration.