I believe in guided spontaneity. For this, the poet must always have some reserves, in his pocket, let’s say, in case of emergency. First, a reserve of mental notes on established poetic forms, of words, sounds, or images, the ones that buzz right past us like bees. They must be caught quickly and put away in one's pocket. I am lazy in this respect, but I know I am passing on some good advice. Mayakovsky had a little notebook he was constantly going into. There is also the reserve of feelings. How can these be preserved? By being conscious of them when they come up. Then, when we face the paper, this consciousness will come back to us more vividly than the emotion itself.
-Pablo Neruda, Memoirs