The best way is always to stop when you are going good and when you know what will happen next. If you do that every day ... you will never be stuck. Always stop while you are going good and don't think about it or worry about it until you start to write the next day. That way your subconscious will work on it all the time. But if you think about it consciously or worry about it you will kill it and your brain will be tired before you start.
Ernest HemingwayWhen I had finished the book I knew that no matter what Scott did, nor how he behaved, I must know it was like a sickness and be of any help I could to him and try to be a good friend. He had many good, good friends, more than anyone I knew. But I enlisted as one more, whether I could be of any use to him or not. If he could write a book as fine as The Great Gatsby I was sure that he could write an even better one. I did not know Zelda yet, and so I did not know the terrible odds that were against him. But we were to find them out soon enough.
Ernest Hemingway