I used to compose a lot. I have several big notebooks piled across the room filled with scores from the days I had a band; I always wrote everything down because of a crappy musical memory.
That got better with time; so I wrote less. Then I stopped - for years! Other ways to express myself came forth.

Meanwhile, I had found my own true instrument, classical guitar, and its study adsorbed any compositive effort.
As a result, it all shifted from the rigidity of a detailed multi-instrument score to the freedom of solo-expression, with a notation that conveys the emotive moods and dynamics I try to communicate... it's far less conventional.

Inserting improvisation was a natural step forward: it allowed a flow unadultered by academic reasonings, and shortened the gap between the head/heart and the fingertips.

Music is no longer my main creative output, so it stays quiet under my skin, sometimes resurfacing, but composition is no longer like in the old days.
Now I just sit down and play, let it flow into time.