In general I think the clustering of success comes from recognition of successful bits during/after repeated practice or iterative production. Once you recognize that you are onto something you can pursue that until you either become bored with it or the market does.

I have had two successes that kicked off hot-streaks and they each came after several years of thrashing around, learning the space and material with which to work. I am in the middle (hopefully) of a new thrashing phase, lots of core competency being built up, (waxonwaxoff) some minor successes, and a whole lot of dissatisfaction.