choosing focus requires personal passion and public reception.
wherever you decide to direct your creative energy, you must be personally, deeply passionate about it. if not, you’ll get bored or burn out; either way, you quit. if you want to write a novel and you hear robot werewolf stories are in but you hate sci-fi, fantasy, horror... you’re not going to last long. you’ve got to direct your writing toward something you’re passionate about, because it’s going to consume a lot of your time and creative energy.
but there must also be public reception to it. again, for instance, let’s say you’re really into robot werewolf stories, but no one wants to read them. you might have passion to write some stories, but with no audience, there’s no accountability. and furthermore, you’ll get discouraged. you’ll end up making stuff only for yourself, which is not usually a good use of creative energy.
“the place God calls you to is the place where your deep gladness and the world’s deep hunger meet.”
― Frederick Buechner, Wishful Thinking: A Theological ABC
you must find things you’re passionate about AND find things people want to consume (i.e., buy, if you’re wanting to make a living from it).
you need to find a personal passion that overlaps with public reception. and the only way to do that is to practice both.
try different things until you find what you’re passionate about. and also create different things until you find something people want. when you find the perfect overlap, get aggressive and keep creating until either you’re no longer passionate or people don’t want it any more.
more
Jack Butcher over at Visualize Value (and those he retweets) has a lot to say about iterating until you find your market where you can make compound interest on whatever you’re creating.