You need to find an author you like. I made a list a few posts back; have you read anything by any of them yet? This isn't the only way, but it's the way I did it and it helped shape my story and style. Reading other authors can make you think about how you write in comparison. I think there are two levels of reading: one where you immerse yourself in the action and just enjoy it like you would a movie, and two where you pay attention to the author's style and what is particularly effective/interesting in terms of language. You need to read in the second way to be able to glean insights from other authors.