Ask yourself: what is my purpose as an artist? This is not a serious question. I will allow you to change your answer or come up with several different answers, but do take a moment to think about it. What are you doing as artist? Write it down. Date it. Put it aside where you'll find it later.
I recently met an artist who felt that the all-important thing was finding out what was wanted and producing that. I don’t agree at this point in my career. If I wanted to produce what the public wants, exclusively, I could be a programmer or a short order cook and do it with art.
It’s a little bit like an “almost right item,” an answer that’s close enough to creating what I want that it festers and itches like a hair shirt. This doesn’t mean that I’m right and my friend was wrong. There may be ways that I will develop when I will look back and wonder why I was so stuck on a particular style.
We tend to stick with what we are comfortable, and I have to admit that I’ve never painted a “night scene.” My advice: develop your skill, but try to stretch yourself periodically. And look at what your purpose is as an artist. There may be many answers.