Rainer Maria Rilke -- Do not write love poems;

Paris, February 17, 1903 from Letters to a Young Poet

...avoid at first those forms that are too facile and commonplace...describe your sorrows and desires, passing thoughts and the belief in some kind of beauty--describe all these with loving, quite, humble sincerity, and use to express yourself, the things in your environment, the images from your dreams, and the objects of your memory. If your daily life seems poor, do not blame it; blame yourself, tell yourself that you are not poet enough to call forth its riches; for to the creator there is no poverty and no poor indifferent place. And even if you were in some prison the walls of which let none of the sounds of the world come to your senses--would you not still then have your childhood, that precious, kingly possession, that treasure house of memories? Try to raise the submerged sensations of that simple; your personality will grow more firm, your solitude will widen and will become a dusky dwelling past which the noise of others goes by far away.