Charles M. Heyworth
A journey of 1000 miles begins with a single step and a book begins with a single word. Even if the first word or page is not worth keeping, it has made it possible to write the second one. Soon, writer's block is a thing of the past.
[example: to answer this question, I began to write the first thing that came to mind. It was the beginning of the idea described above, but it wasn't until the 3rd or 4th rewrite that the idea was actually clear.]