Do you have an ideal reader? When you're writing (or doing something else creative) do you have a specific audience in mind who you want to impress/move to tears/have howling with laughter more than anything?
I'm not really one of those writers. With my first novel, The Art of Letting Go, I wrote the book I wanted to write and then desperately tried to figure out the target market. Not a very professional approach! However, sometimes when I'm writing, somebody real will come to mind who I think will like, or be intrigued by what I'm trying to do. With The Art of Letting Go, I couldn't stop imagining my eldest sibling reading it, and in very subtle ways that shaped the novel as it progressed. I've found similar things with various other people while writing short stories too. Sometimes it can be a subject matter that will interest them, other times it's just a feeling about the style or the themes behind the plot. The major drawback of having real ideal readers, is that one day you might well find out whether or not they actually do like your book. Then they might prove to be less than ideal after all!
An ideal reader is the writer's equivalent to an imaginary friend.They are the people you can imagine reading your work and finding it fabulous. Imaginary friends don't get bored, point out typos before they've pointed out how scintillating your prose is, or say they prefer a Mills and Boon. Most importantly, they keep a writer conscious of the fact they are writing to be read. Unless your work is entirely private, a connection to your future readers is essential.
Who's your ideal reader?