One thing that I found helped me become a better writer was to look at the epically infamous My Immortal. After I had read it the first time, I sat silently, marveling in how horrible it was. Then, I had an idea. I went back and read through it again, thinking of all the ways I could do better. (Well, way better, anyways...)
It gave me insight on what the worst could possibly be, and it fueled me to not stoop down to that level. Even with all it's punctuation and spelling errors, My Immortal helped me to set a goal, which was to do better and better no matter what.