The most important thing to keep in mind when writing

It is this: HAVE FUN! I am serious. The moment you grow self conscious and try to make sure your words correspond to some random standard in your head, the story stops flowing and the prose becomes laboured. It is only when you leave your mind out and allow yourself to become an instrument of the tale, that the story comes out as it should.

It may seem an obvious thing, but forgetting to have fun is one of the most common occupational hazards I have encountered while writing a story.