We can never become complacent as writers. We should always work to improve our skills. As we do so, we experience what Covey calls the "upward spiral" of progression.
Self-improvement doesn't happen by accident. We must make conscious choices about what we want to improve and how we're going to go about it. There are many resources out there for writers who want to improve their craft--we have lots of them here at Operation Awesome, for one--it's just a matter of finding something that works for you and having the tenacity to stick with it.
Good luck to you!