As you will already know, the plot is the main story of a novel. The question is whether you should work out a detailed plot before you start to write or not.
If you are aiming to write a blockbuster, then the answer is a resounding YES. You will remember the first tip: “The Story is Everything” and how without a properly worked out story, you have nothing. Working out that story is called plotting.

Whether or not you plot in advance, once you have written your novel, it will have a storyline. The difference between a novel that’s written “on the hoof” without detailed planning and one that’s closely-plotted, could well be the difference between one that will never be published and one that sells a million copies.
Bestsellers, especially in the fields of thrillers, suspense, mystery, adventure and so on, are invariably carefully plotted. Their authors spent a long time working out stories that will please and excite their readers.
I’m always amazed at writers who would not set out on a fifty mile journey without an up-to-date road map and yet think nothing of embarking on a novel without any idea as to their eventual destination. And there are a thousand more chances of getting lost in a novel as there are in a fifty mile road trip!
Remember the old saying: “Fail to plan, plan to fail”
In my view, having a plot is crucial. It doesn’t have to be detailed, at least to start with. Something as simple as “During World War II the German High Command parachute an elite group of stormtroopers into England to assassinate Churchill” (The Eagle Has Landed by Jack Higgins).
The Thriller writer Ken Follett uses a similar technique to plot his books. He starts with a single phrase and keeps building on it until he ends up with a multi-page synopsis he can write from. He turns the sentence into a paragraph, then into two paragraphs, and so on…
All the time you have to ask yourself, “What can happen now?” To add an extra dimension, make this a two-stage process. Think of the most obvious outcome, ignore that, then think of something else. Avoid making your story predictable or boring in every way you can.For detailed plotting advice, check out my book, Million Dollar Story