Being consistent with the percussion

One aspect of Night Sky that I am trying to be consistent with is the doubling and the use of the percussion. In particular, how often do I use the instruments and which mallet instruments double which wind group.

In regards to the first question: "How often do I use the instruments?" I am primarily concerned with using the instrument multiple times.  I do not want to have the ensemble bring out, for example, a marimba if it is going to be used to accent just one note in the entire piece.  I have known composers who have done this and it is such a waste of time and effort.

In Night Sky I have found that I did this with the triangle at measure 9.  While it is a small instrument I do not think that it is imperative that measure 9 needs that sound.  Before I replace the triangle with another instrument I will search the score to see if there are other places in which I can utilize the triangle.

As for the mallet instruments, I am not interested in using only the vibraphone or only the glockenspiel with certain wind groups throughout the piece.  Rather, in addressing this second question I am referring to specific sections.  If the vibraphone doubles the clarinets in one section of the piece, then do not want it to double, for example, the alto sax in the same section.  When the music reaches a different section, then the vibraphone can double other instruments.  Often this is an easy problem to fix as I can shift the mallet doubling to another instrument.

These are all things that I try to focus on during the editing process in hope that my piece will sound better.