From my experience of teaching, I am a firm believer that no teacher ever "arrives!" Therefore, those great teachers out there are the ones who are constantly learning and figuring out what methods work with those kids they have been entrusted with. Each child is different, and each new group of children from year to year, are uniquely different. I have found that year after year, my files are pretty much scrapped...and its time to begin again.
For more on this subject: http://www.theatlantic.com/doc/201001/good-teaching