At the start of writing any book, there are always certain scenes that you have in mind before the first word is ever written. A big problem new writers have is their impatience to get to these scenes. They rush through things so that they can write the part that is super clear to them. But stories don't work like that...a lot of the time, those scenes need to be built. Some serious groundwork needs laid if they are going to have the impact one hopes for them to have.
This type of scene can be a blessing...after all, every writer loves to keep a fully formed scene in their pocket to pull out when needed. But they can behave like demons as well, constantly banging on the door and wanting to throw themselves all over the next blank page. It can be a tough task keeping that door shut. The temptation to let them in too early is often overwhelming.
The other day, I reached the point in my manuscript where I could cast that door wide open and work on a scene that had been in my mind from the outset. It was a great feeling taming that demon. The struggle to keep it at bay is always worth it in the end.