Write as if you've never written before.
Write as if you'll never write again.
Write as if the person you love most in life ends up as the person you hate most at the wake of death.
Write as if nobody will ever see your work.
Write as if you've died more times in your own life than you've lived.
Write as if the music is still there.
Write as if you've suffered through your years.
Write as if you have the worst dayjob on earth.
Write as if it reads the reader. Rather than the reader reading your work.