This is what I do. When I learn something, whatever (a scale, a mode, a rhythm, added chords, chords by fiftsh, etc.........) I write short things to aprehend those elements and to feel how they work and sound. These are not compositions, only exercises. I don't care if they are good or not.
With time, I try to combine what I have been learning. This is, perhaps, more difficult, but it is the essence of composition: taking many tools you know, and pick those that fit in you idea.