There is no sense in trying to catch the wind. In that I mean that the best way to achieve the target is to have a clear sense of the audience you are trying to catch. It is also the best way to come up with ideas.
Take genre fiction for example. In genre fiction there is a ready audience. If you sit down and try to come up with an idea that will be noticed and get published, but not only that: sell as well. With genre fiction you have a ready market in every area. Romance, horror, sci-fi and every other genre out there have a particular publisher and ready fan base for each of them. Mills and Boon publishes hundreds of titles a year and accepts many unpublished or little heard of authors. Stephen King, the master of the macabre started out with a punchy little vampire novel.
That is the great thing about genre fiction and brings up another great time saver. Genre fiction has a formula; a set way of doing things that makes the task of writing them that much faster. As in romance, we all know the boy meets girl, boy loses girl, boy gets girl back formula. They might sound corny but it’s what the public wants out of their genre fiction. That’s not to say that you don’t add your own unique style and flavor. Formula is what is what gets the reader into a certain genre, adding your own unique twists are what gets the reader into you.