Since my days as a student I have concerned myself with various styles and notations. In doing so I try to find my own ways of composing. A professor of the conservatory once told me: "Music is a game!" That statement made me see the difference between "playing music" as musicians do and the second meaning of playing in the sense of children playing with toys or people playing cards at a casino. Since then, I've been uncaged from the conventional styles and notes. I didn't feel obligated to compose in strict styles anymore.
The timbre always plays an important role in my compositions. Sometimes the combination of the instruments acts as this role of timbre, but it can also be accords, rythms, dynamics, pitch, etc. Every now and then I also allow the musicians some latitude to play with my music.