So, as I continue to send out queries for Defender of the Crown, I'm considering my other book ideas to give me something to do. Right now I really want to write Flatiron City, but I'm not sure what the best direction is for that book (hopefully series) yet. So I believe I'll move in a different direction and put together a novel that will have little to no potential to become a series. A stand-alone story with no potential for a sequel. (Even though Defender stands alone, it will hopefully become a series of books. Not holding my breath, yet.) In fact, Nathan Bransford talked about this only yesterday. I really agree with what he said, too.
However, this is quite a leap for me because every book I've tried to write, except for the first one, was intended to become a series, even though I never had any thoughts or ideas for a second book or beyond. I kind of had an idea of where it COULD go, but always planned to write the first one and see what happened later. When you don't plan on making more than one book with the same characters, though, you make different decisions about what to tell the reader about your world and your characters (though that may not always be the case).
I've met a couple of writers who believe that every book, regardless of the style, genre, or whether or not it's intended to stand alone, should all be written exactly the same way. Without planning anything out before you sit down to write. That may work for them, but that's not how my brain works. I need to know who the protagonist and antagonist are, at the very least, before I sit down and create my story. I really like to know what the protagonist does in his free time (all of my heroes, so far, have been male), and I like to have an idea of where they came from and where they plan on going...so that I can throw a stick of dynamite into those plans and create a novel :D.
Anyway, some time this summer, I plan on sitting down and writing a new book. Something to keep me writing while I try to get published. This one will stand alone. I won't write more than one book with these characters. I just don't know who my audience is, yet. Should it be the 14-18 year-olds? The 16-25s? Or possibly the 18-99s? I'm thinking more along the lines of 15-30ish...but we'll see.