Smith cites in her essays the feeling of having her writing "grow up" in front of in audience; she was first published fairly young, in her late twenties, when her writing style was still developing, and that development has taken place with a lot of people watching.
I have often wondered, if I were to be published one day, what would I do with the things I am writing right now? Would they be good enough to be published? Would people even care to read them?
I purchased a complete collection of Sylvia Plath's poems over the summer, which includes a number of poems Plath wrote in college. I enjoyed them, but the maturation of her style and skill as she went on was apparent.
Being a student still, I know that most of what I'm writing right now is still "practice", and that it will not be perfect. Better ideas and a more mature style will come with time. It's comforting, in a way, to see that even Plath and Smith had to go through a similar process.
It really comes down to being willing to push through the blocks and the flaws to just keep writing.
A review of the book can be found here.