This is one of those quotes that is about writing but can be about everything in life that requires preparation, work, revision, and the courage to surrender the results.  Anything where we choose can be around these words.  Anything that calls forth effort is like writing and requires careful editing.  A decision where to take the person you love for a quiet, meaningful conversation.  The answer to a penetrating question.  Picking what to where for an important meeting.  Not rushing is essential because it means we run through the slow work of foundation-building.  From Writers Digest:

But building a career requires that you lay a strong foundation of only your best work--and nobody’s first draft is the best it can be. Careful editing is the mortar that holds the story bricks together.