P is for Plot. There are probably other writing tips for this letter but for me Plot is important. A plot is a road map that takes you from point A, the beginning to point B, the end. Knowing how the story starts and having an idea of the ending. Sometimes the beginning changes as the story is explored. The ending can also change. I usually have a very general idea about the ending. This may be something like the bad guy is caught. Or the heroine gets the hero. Or the space ship reaches it's destination.
Having a general idea of where the story is headed can then be blocked out. There are times when I see the ending as a clear picture. Then I know the beginning has to have clues of the way to reach the ending.
Since plot is a road map, sketching the important points happening to take the characters from that beginning moment to the end helps. As with any story, there can be changes along the way. The initial hero or heroine may be wrong for each other as the story progresses. Sometimes while writing a mystery, I have no idea who the villain will be. This is good since mysteries need red herrings along the way.
So when you sit down to tell your story, think ahead from that beginning to what will happen at the end. For most stories, the story will flow easily. But don't forget you can change the direction, as long as you don't end up in a dead end.