Writer S.C. Butler has some advice that writers everywhere should pay attention to: Write the kinds of books you actually enjoy reading, not the books you think will sell, or the ones you have a killer idea for.
I tried to write a thriller. It was the last book I worked on before starting Reiffen's Choice, the first book I sold. The problem was, I don't like thrillers. Never have, never will. At least not reading them. (I've always loved thriller movies.) But I had this great idea, and a great ending. A shootout on top of Mt. Washington in a June snowstorm. Very visual. I was sure I could sell it.
But first I had to write it. Boy, was that painful. Like I said, I hate thrillers. My idea was about a serial killer who murders child molesters, and the biggest problem was that I had to write all these molestation flashbacks and come up with about half a dozen creative, graphic murders. Very nasty. I stated really dreading my time at the keyboard.
Even worse, it was boring. I was boring myself, which is a terrible sign. If you don't jump up and punch the air in celebration once every couple of weeks about a scene you've just written, chances are no one else is going to punch the air about it, either. If the writer's bored, pity the poor reader.
Thank goodness Butler finally switched to working on the fantasy novel he was actually excited about before his gritty gun-toting thriller hero nearly killed him. Anyway, "write what you love" seems like basic advice, but it's something many writers ignore to their cost.