I like to play from feeling. I’m not so excited by the idea of ‘thinking’ when coming up with some music, be it improvised or composed.
So you might try composing by getting yourself into a state where you feel something particularly deeply, but then there’s no need for any music, really. Whenever I’ve tried that, I go to touch the instrument and everything sounds absurd.
The other way round works better for me.
Play a chord progression, note, thing, whatever, again and again until it ceases to be a chord progression. Play it until it becomes a feeling.