When you start something, make sure that you finish it. It doesn't matter how long it takes. Never give up. Don't be beaten. Be the writer. I know writers who complete everything, and I know those that complete nothing. Those that complete everything have a story to tell. Be that guy.
Don't be jealous of other people's work. Read it. Enjoy it. Learn from it. Love it. Writing is hard, we all know that, enjoy in their success as you would have them enjoy yours. Work to be better yourself.
Experiment. Try weird new things. (No, not that: writing). Stick your quill into the ink of fantasy, horror, erotica, romance, drama and comedy. How do you know if you're any good at it, until you try it. Try everything once. Twice if you like it.