1st one concerns the articulation. Important aspect to consider is that the musicians are sight reading. They are most probably seeing the notes for the first time as opposed to the composer. So it is quite important that the specific articulation for each of the instruments is written down.

The second important thing when it comes to orchestration is to always think about the possibilities of the instruments and also their differences. How the ranges of the instruments and even the human voice could be taken into account…

The third tip is regarding the harmonic balance within the orchestra. The harmony needs to be thought out in such a way that no note from the chord gets too overpowering compared to the others. In order to do so, the orchestrator or the composer should pay attention to where the instruments are located in their range. Another thing that is often neglected is the harmony - which of the notes within a chord should be used emphasised more than the others.

Check out more details and specific examples in the video below.